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1.
Trials ; 20(1): 243, 2019 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-31036037

RESUMEN

BACKGROUND: Venous leg ulcers are slow-healing wounds with a high recurrence rate of 70% and a 60% risk of becoming chronic. Signs and symptoms such as pain or exudate are not only a burden on those affected but also on the healthcare system and society in general. The estimated leg ulcer prevalence in the general population is 1%. Treatment costs for leg ulcers are estimated to be 3% of overall health expenditure. Current therapeutic approaches are multifaceted and include compression therapy, leg elevation, specific ankle-exercises and a protein diet. They require an interdisciplinary team of health care professionals. Approximately 70% of patients have a knowledge deficit with regards to therapeutic measures and have difficulties with adherence to treatment protocols. Therefore, it is of utmost importance that the treatment team provides effective patient education and support during the learning phase. However, there is little evidence and no published studies that describe and evaluate effective interdisciplinary educational interventions that target compliance/adherence to the treatment plan in patients with leg ulcers. We therefore propose to develop an evidence-based interprofessional educational intervention and evaluate its feasibility first in a pilot study and subsequently in a randomized controlled trial. METHOD/DESIGN: First, the development of an evidence-based educational intervention in collaboration with an expert panel is proposed and second, a randomized controlled feasibility study in a wound-care outpatient clinic. Eligible patients (n = 20) with leg ulcers will be randomized to receive either interdisciplinary education and usual care or only usual care, for 12 weeks. Data will be analyzed using SPSS version 25. Univariate and bivariate analysis will be conducted according to the data level and distribution of the data. DISCUSSION: We will first develop an evidenced-based educational intervention and second, we will examine the feasibility of implementing this educational intervention in a realistic care context in patients with leg ulcers. The results will inform the final design of a subsequent randomized controlled trial, which will examine the effectiveness of the educational intervention. An intervention that enhances patient adherence to therapy would be beneficial to individual patients and to society as a whole. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03454698 . Registered on 6 March 2018.


Asunto(s)
Úlcera de la Pierna/terapia , Cooperación del Paciente , Educación del Paciente como Asunto/métodos , Cicatrización de Heridas , Estudios de Factibilidad , Conocimientos, Actitudes y Práctica en Salud , Humanos , Úlcera de la Pierna/diagnóstico , Úlcera de la Pierna/fisiopatología , Úlcera de la Pierna/psicología , Grupo de Atención al Paciente , Proyectos Piloto , Ensayos Clínicos Controlados Aleatorios como Asunto , Suiza , Factores de Tiempo , Resultado del Tratamiento
2.
Atherosclerosis ; 249: 200-8, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27108950

RESUMEN

BACKGROUND: Atherosclerosis is characterized by lipid accumulation and chronic inflammation in the arterial wall. Elevated levels of apolipoprotein (apo) B-containing lipoproteins are a risk factor for cardiovascular disease (CVD). By contrast, plasma levels of functional high-density lipoprotein (HDL) and apoA-I are protective against CVD by enhancing reverse cholesterol transport (RCT). Activation of peroxisome proliferator-activated receptor-α (PPARα), a ligand-activated transcription factor, controls lipid metabolism, cellular cholesterol trafficking in macrophages and influences inflammation. OBJECTIVE: To study whether pharmacological activation of PPARα with a novel highly potent and selective PPARα modulator, pemafibrate, improves lipid metabolism, macrophage cholesterol efflux, inflammation and consequently atherosclerosis development in vitro and in vivo using human apolipoprotein E2 Knock-In (apoE2KI) and human apoA-I transgenic (hapoA-I tg) mice. APPROACH AND RESULTS: Pemafibrate treatment decreases apoB secretion in chylomicrons by polarized Caco-2/TC7 intestinal epithelium cells and reduces triglyceride levels in apoE2KI mice. Pemafibrate treatment of hapoA-I tg mice increases plasma HDL cholesterol, apoA-I and stimulates RCT to feces. In primary human macrophages, pemafibrate promotes macrophage cholesterol efflux to HDL and exerts anti-inflammatory activities. Pemafibrate also reduces markers of inflammation and macrophages in the aortic crosses as well as aortic atherosclerotic lesion burden in western diet-fed apoE2KI mice. CONCLUSIONS: These results demonstrate that the novel selective PPARα modulator pemafibrate exerts beneficial effects on lipid metabolism, RCT and inflammation resulting in anti-atherogenic properties.


Asunto(s)
Aterosclerosis/tratamiento farmacológico , Benzoxazoles/farmacología , Butiratos/farmacología , Colesterol/metabolismo , Dislipidemias/tratamiento farmacológico , Inflamación/tratamiento farmacológico , PPAR alfa/antagonistas & inhibidores , Animales , Apolipoproteína A-I/química , Transporte Biológico , Células CACO-2 , Enfermedades Cardiovasculares/sangre , Epitelio/metabolismo , Femenino , Homocigoto , Humanos , Mucosa Intestinal/metabolismo , Ligandos , Metabolismo de los Lípidos , Lipoproteínas HDL/sangre , Lipoproteínas HDL/metabolismo , Macrófagos/metabolismo , Ratones , PPAR alfa/metabolismo , Factores de Riesgo
3.
Rech Soins Infirm ; (127): 55-70, 2016 Dec.
Artículo en Francés | MEDLINE | ID: mdl-28186482

RESUMEN

Persons with advanced cancer experience high levels of existential distress due to being confronted with their mortality, which leads to feelings of lack of sense, or discouragement. It is important to develop interventions to relieve existential distress to promote the dignity of persons with advanced cancer in order to help them live this difficult experience in the best possible way. A new intervention, called Revie ⊕ and conducted by nurses, was developed. A feasibility study was conducted with 41 patients with advanced cancer in the ambulatory and hospital sector of a university hospital in Switzerland to determine the acceptability of Revie ⊕. The purpose of this article is to present the intervention's acceptability from the perspective of the nurses. Nurses conducting the intervention were asked to complete a questionnaire, maintain personal notes, and to participate in one focus group. Descriptive statistics were used to analyze the questionnaire. Thematic analysis was applied to analyze the nurses' personal notes and focus group data. Results indicate that nurses consider Revie ⊕ to be a beneficial intervention for the patients and also for their professional posture. As a consequence, the nurses wish for its implementation into practice. Recommendations are proposed to promote further implementation.


Asunto(s)
Actitud del Personal de Salud , Neoplasias/enfermería , Enfermeras y Enfermeros/psicología , Percepción , Adulto , Actitud Frente a la Muerte , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Medicina Narrativa , Proyectos Piloto , Encuestas y Cuestionarios , Suiza , Cuidado Terminal/métodos
4.
Gastroenterology ; 150(3): 650-8, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26602218

RESUMEN

BACKGROUND & AIMS: Reducing postprandial triglyceridemia may be a promising strategy to lower the risk of cardiovascular disorders associated with obesity and type 2 diabetes. In enterocytes, scavenger receptor class B, type 1 (SR-B1, encoded by SCARB1) mediates lipid-micelle sensing to promote assembly and secretion of chylomicrons. The nuclear receptor subfamily 1, group H, members 2 and 3 (also known as liver X receptors [LXRs]) regulate genes involved in cholesterol and fatty acid metabolism. We aimed to determine whether intestinal LXRs regulate triglyceride absorption. METHODS: C57BL/6J mice were either fed a cholesterol-enriched diet or given synthetic LXR agonists (GW3965 or T0901317). We measured the production of chylomicrons and localized SR-B1 by immunohistochemistry. Mechanisms of postprandial triglyceridemia and SR-B1 regulation were studied in Caco-2/TC7 cells incubated with LXR agonists. RESULTS: In mice and in the Caco-2/TC7 cell line, LXR agonists caused localization of intestinal SR-B1 from apical membranes to intracellular organelles and reduced chylomicron secretion. In Caco-2/TC7 cells, LXR agonists reduced SR-B1-dependent lipidic-micelle-induced Erk phosphorylation. LXR agonists also reduced intracellular trafficking of the apical apolipoprotein B pool toward secretory compartments. LXR reduced levels of SR-B1 in Caco-2/TC7 cells via a post-transcriptional mechanism that involves microRNAs. CONCLUSION: In Caco-2/TC7 cells and mice, intestinal activation of LXR reduces the production of chylomicrons by a mechanism dependent on the apical localization of SR-B1.


Asunto(s)
Absorción Intestinal , Mucosa Intestinal/metabolismo , Yeyuno/metabolismo , Receptores Nucleares Huérfanos/metabolismo , Receptores Depuradores de Clase B/metabolismo , Triglicéridos/metabolismo , Animales , Apolipoproteína B-100/metabolismo , Apolipoproteínas B/metabolismo , Benzoatos/farmacología , Bencilaminas/farmacología , Células CACO-2 , Colesterol en la Dieta/metabolismo , Quilomicrones/metabolismo , ARN Helicasas DEAD-box/deficiencia , ARN Helicasas DEAD-box/genética , Regulación hacia Abajo , Humanos , Hidrocarburos Fluorados/farmacología , Absorción Intestinal/efectos de los fármacos , Mucosa Intestinal/efectos de los fármacos , Yeyuno/efectos de los fármacos , Receptores X del Hígado , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , MicroARNs/genética , MicroARNs/metabolismo , Receptores Nucleares Huérfanos/agonistas , Transporte de Proteínas , Interferencia de ARN , Ribonucleasa III/deficiencia , Ribonucleasa III/genética , Receptores Depuradores de Clase B/deficiencia , Receptores Depuradores de Clase B/genética , Transducción de Señal , Sulfonamidas/farmacología , Transcripción Genética , Transfección
5.
Int J Cardiol ; 188: 111-6, 2015 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-25919891

RESUMEN

OBJECTIVE: HDL functionality has been shown to be impaired in inflammatory conditions, including coronary artery disease. The present study aims to determine the impact of low grade and acute inflammation on HDL function and structure. APPROACH AND RESULTS: i) The endothelial protective effects of HDL were compared between 26 periodontal patients and 26 age and sex matched controls by measuring paraoxonase activity in serum and nitric oxide bioavailability and superoxide production in endothelial cells. Paraoxonase activity and nitric oxide bioavailability were reduced, while superoxide production was increased (p<0.01) in periodontal patients compared to controls. ii) HDL function, including cholesterol efflux and vascular cell adhesion molecule-1 expression, was subsequently measured in the periodontal patients following an inflammatory stimulus. There was an acute deterioration in HDL's endothelial protective function, without change in cholesterol efflux, after 24h (p<0.01 for all). These functional changes tracked increases of inflammatory markers and altered HDL composition. Finally, HDL function returned to baseline levels after resolution of inflammation. CONCLUSION: This study demonstrates that even minor alterations in systemic inflammation can impair the endothelial protective effects of HDL. These functional changes were independent of cholesterol efflux and were associated with remodeling of the HDL proteome. All measures of HDL's endothelial protective functions recovered with resolution of inflammation. These findings suggest that HDL dysfunction may represent a novel mechanism linking inflammation with progression of atheroma.


Asunto(s)
Arildialquilfosfatasa/metabolismo , Lipoproteínas HDL/sangre , Periodontitis/sangre , Periodontitis/fisiopatología , Adulto , Estudios de Casos y Controles , Enfermedad Crónica , Células Endoteliales/metabolismo , Femenino , Estudios de Seguimiento , Humanos , Inflamación/sangre , Inflamación/fisiopatología , Mediadores de Inflamación/sangre , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Óxido Nítrico/metabolismo , Índice de Severidad de la Enfermedad , Factores de Tiempo , Molécula 1 de Adhesión Celular Vascular/metabolismo
6.
Circulation ; 131(10): 871-81, 2015 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-25673670

RESUMEN

BACKGROUND: Roux-en-Y gastric bypass (RYGB) reduces body weight and cardiovascular mortality in morbidly obese patients. Glucagon-like peptide-1 (GLP-1) seems to mediate the metabolic benefits of RYGB partly in a weight loss-independent manner. The present study investigated in rats and patients whether obesity-induced endothelial and high-density lipoprotein (HDL) dysfunction is rapidly improved after RYGB via a GLP-1-dependent mechanism. METHODS AND RESULTS: Eight days after RYGB in diet-induced obese rats, higher plasma levels of bile acids and GLP-1 were associated with improved endothelium-dependent relaxation compared with sham-operated controls fed ad libitum and sham-operated rats that were weight matched to those undergoing RYGB. Compared with the sham-operated rats, RYGB improved nitric oxide (NO) bioavailability resulting from higher endothelial Akt/NO synthase activation, reduced c-Jun amino terminal kinase phosphorylation, and decreased oxidative stress. The protective effects of RYGB were prevented by the GLP-1 receptor antagonist exendin9-39 (10 µg·kg(-1)·h(-1)). Furthermore, in patients and rats, RYGB rapidly reversed HDL dysfunction and restored the endothelium-protective properties of the lipoprotein, including endothelial NO synthase activation, NO production, and anti-inflammatory, antiapoptotic, and antioxidant effects. Finally, RYGB restored HDL-mediated cholesterol efflux capacity. To demonstrate the role of increased GLP-1 signaling, sham-operated control rats were treated for 8 days with the GLP-1 analog liraglutide (0.2 mg/kg twice daily), which restored NO bioavailability and improved endothelium-dependent relaxations and HDL endothelium-protective properties, mimicking the effects of RYGB. CONCLUSIONS: RYGB rapidly reverses obesity-induced endothelial dysfunction and restores the endothelium-protective properties of HDL via a GLP-1-mediated mechanism. The present translational findings in rats and patients unmask novel, weight-independent mechanisms of cardiovascular protection in morbid obesity.


Asunto(s)
Peso Corporal/fisiología , Endotelio Vascular/fisiología , Péptido 1 Similar al Glucagón/fisiología , Lipoproteínas HDL/fisiología , Obesidad/cirugía , Pérdida de Peso/fisiología , Adulto , Animales , Antioxidantes/fisiología , Estudios de Casos y Controles , Células Cultivadas , Dieta Alta en Grasa/efectos adversos , Modelos Animales de Enfermedad , Endotelio Vascular/patología , Femenino , Derivación Gástrica , Humanos , Masculino , Óxido Nítrico/fisiología , Obesidad/fisiopatología , Estrés Oxidativo/fisiología , Proteínas Proto-Oncogénicas c-akt/fisiología , Ratas , Ratas Wistar , Transducción de Señal , Resultado del Tratamiento
7.
Nat Rev Cardiol ; 12(1): 10-7, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25367649

RESUMEN

Macrophage accumulation within the vascular wall is a hallmark of atherosclerosis. In atherosclerotic lesions, macrophages respond to various environmental stimuli, such as modified lipids, cytokines, and senescent erythrocytes, which can modify their functional phenotypes. The results of studies on human atherosclerotic plaques demonstrate that the relative proportions of macrophage subsets within a plaque might be a better indicator of plaque phenotype and stability than the total number of macrophages. Understanding the function of specific macrophage subsets and their contribution to the composition and growth of atherosclerotic plaques would aid the identification of novel strategies to delay or halt the development of the disease and its associated pathophysiological consequences. However, most studies aimed at characterizing the phenotypes of human macrophages are performed in vitro and, therefore, their functional relevance to human pathology remains uncertain. In this Review, the diverse range of macrophage phenotypes in atherosclerotic lesions and their potential roles in both plaque progression and stability are discussed, with an emphasis on human pathology.


Asunto(s)
Aterosclerosis/patología , Macrófagos/patología , Placa Aterosclerótica/patología , Citocinas/metabolismo , Progresión de la Enfermedad , Humanos , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Metabolismo de los Lípidos , Activación de Macrófagos , Macrófagos/metabolismo
8.
Handb Exp Pharmacol ; 224: 617-30, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25523004

RESUMEN

Dyslipidaemia is a major risk factor for cardiovascular diseases. Pharmacological lowering of LDL-C levels using statins reduces cardiovascular risk. However, a substantial residual risk persists especially in patients with type 2 diabetes mellitus. Because of the inverse association observed in epidemiological studies of HDL-C with the risk for cardiovascular diseases, novel therapeutic strategies to raise HDL-C levels or improve HDL functionality are developed as complementary therapy for cardiovascular diseases. However, until now most therapies targeting HDL-C levels failed in clinical trials because of side effects or absence of clinical benefits. This chapter will highlight the emerging small molecules currently developed and tested in clinical trials to pharmacologically modulate HDL-C and functionality including new CETP inhibitors (anacetrapib, evacetrapib), novel PPAR agonists (K-877, CER-002, DSP-8658, INT131 and GFT505), LXR agonists (ATI-111, LXR-623, XL-652) and RVX-208.


Asunto(s)
Enfermedades Cardiovasculares/prevención & control , Diseño de Fármacos , Dislipidemias/tratamiento farmacológico , Hipolipemiantes/uso terapéutico , Animales , Enfermedades Cardiovasculares/etiología , Enfermedades Cardiovasculares/metabolismo , Proteínas de Transferencia de Ésteres de Colesterol/antagonistas & inhibidores , Proteínas de Transferencia de Ésteres de Colesterol/metabolismo , Dislipidemias/complicaciones , Dislipidemias/metabolismo , Humanos , Hipolipemiantes/química , Receptores X del Hígado , Terapia Molecular Dirigida , Receptores Nucleares Huérfanos/agonistas , Receptores Nucleares Huérfanos/metabolismo , Receptores Activados del Proliferador del Peroxisoma/agonistas , Receptores Activados del Proliferador del Peroxisoma/metabolismo , Quinazolinas/uso terapéutico , Quinazolinonas , Transducción de Señal/efectos de los fármacos
9.
Immunol Rev ; 262(1): 153-66, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25319333

RESUMEN

Initiation and progression of atherosclerosis depend on local inflammation and accumulation of lipids in the vascular wall. Although many cells are involved in the development and progression of atherosclerosis, macrophages are fundamental contributors. For nearly a decade, the phenotypic heterogeneity and plasticity of macrophages has been studied. In atherosclerotic lesions, macrophages are submitted to a large variety of micro-environmental signals, such as oxidized lipids and cytokines, which influence the phenotypic polarization and activation of macrophages resulting in a dynamic plasticity. The macrophage phenotype spectrum is characterized, at the extremes, by the classical M1 macrophages induced by T-helper 1 (Th-1) cytokines and by the alternative M2 macrophages induced by Th-2 cytokines. M2 macrophages can be further classified into M2a, M2b, M2c, and M2d subtypes. More recently, additional plaque-specific macrophage phenotypes have been identified, termed as Mox, Mhem, and M4. Understanding the mechanisms and functional consequences of the phenotypic heterogeneity of macrophages will contribute to determine their potential role in lesion development and plaque stability. Furthermore, research on macrophage plasticity could lead to novel therapeutic approaches to counteract cardiovascular diseases such as atherosclerosis. The present review summarizes our current knowledge on macrophage subsets in atherosclerotic plaques and mechanism behind the modulation of the macrophage phenotype.


Asunto(s)
Aterosclerosis/etiología , Macrófagos/inmunología , Macrófagos/metabolismo , Fenotipo , Animales , Aterosclerosis/patología , Movimiento Celular , Humanos , Activación de Macrófagos , Placa Aterosclerótica/inmunología , Placa Aterosclerótica/metabolismo , Placa Aterosclerótica/patología , Factores de Transcripción/metabolismo
10.
J Am Soc Nephrol ; 25(11): 2658-68, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24854267

RESUMEN

Endothelial dysfunction begins in early CKD and contributes to cardiovascular mortality. HDL is considered antiatherogenic, but may have adverse vascular effects in cardiovascular disease, diabetes, and inflammatory conditions. The effect of renal failure on HDL properties is unknown. We studied the endothelial effects of HDL isolated from 82 children with CKD stages 2-5 (HDL(CKD)), who were free of underlying inflammatory diseases, diabetes, or active infections. Compared with HDL from healthy children, HDL(CKD) strongly inhibited nitric oxide production, promoted superoxide production, and increased vascular cell adhesion molecule-1 expression in human aortic endothelial cells, and reduced cholesterol efflux from macrophages. The effects on endothelial cells correlated with CKD grade, with the most profound changes induced by HDL from patients on dialysis, and partial recovery observed with HDL isolated after kidney transplantation. Furthermore, the in vitro effects on endothelial cells associated with increased aortic pulse wave velocity, carotid intima-media thickness, and circulating markers of endothelial dysfunction in patients. Symmetric dimethylarginine levels were increased in serum and fractions of HDL from children with CKD. In a longitudinal follow-up of eight children undergoing kidney transplantation, HDL-induced production of endothelial nitric oxide, superoxide, and vascular cell adhesion molecule-1 in vitro improved significantly at 3 months after transplantation, but did not reach normal levels. These results suggest that in children with CKD without concomitant disease affecting HDL function, HDL dysfunction begins in early CKD, progressing as renal function declines, and is partially reversed after kidney transplantation.


Asunto(s)
HDL-Colesterol/sangre , Insuficiencia Renal Crónica/sangre , Insuficiencia Renal Crónica/mortalidad , Enfermedades Vasculares/sangre , Enfermedades Vasculares/mortalidad , Adolescente , Arginina/análogos & derivados , Arginina/sangre , Biomarcadores/sangre , Niño , LDL-Colesterol/sangre , Endotelio Vascular/metabolismo , Femenino , Humanos , Trasplante de Riñón/mortalidad , Masculino , Óxido Nítrico/metabolismo , Diálisis Renal/mortalidad , Insuficiencia Renal Crónica/cirugía , Triglicéridos/sangre , Enfermedades Vasculares/cirugía
11.
Biochim Biophys Acta ; 1841(6): 827-35, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24603323

RESUMEN

Liver X receptors (LXRα and LXRß) are key transcription factors in cholesterol metabolism that regulate cholesterol biosynthesis/efflux and bile acid metabolism/excretion in the liver and numerous organs. In macrophages, LXR signaling modulates cholesterol handling and the inflammatory response, pathways involved in atherosclerosis. Since regulatory pathways of LXR transcription control are well understood, in the present study we aimed at identifying post-transcriptional regulators of LXR activity. MicroRNAs (miRs) are such post-transcriptional regulators of genes that in the canonical pathway mediate mRNA inactivation. In silico analysis identified miR-206 as a putative regulator of LXRα but not LXRß. Indeed, as recently shown, we found that miR-206 represses LXRα activity and expression of LXRα and its target genes in hepatic cells. Interestingly, miR-206 regulates LXRα differently in macrophages. Stably overexpressing miR-206 in THP-1 human macrophages revealed an up-regulation and miR-206 knockdown led to a down-regulation of LXRα and its target genes. In support of these results, bone marrow-derived macrophages (BMDMs) from miR-206 KO mice also exhibited lower expression of LXRα target genes. The physiological relevance of these findings was proven by gain- and loss-of-function of miR-206; overexpression of miR-206 enhanced cholesterol efflux in human macrophages and knocking out miR-206 decreased cholesterol efflux from MPMs. Moreover, we show that miR-206 expression in macrophages is repressed by LXRα activation, while oxidized LDL and inflammatory stimuli profoundly induced miR-206 expression. We therefore propose a feed-back loop between miR-206 and LXRα that might be part of an LXR auto-regulatory mechanism to fine tune LXR activity.


Asunto(s)
Colesterol/metabolismo , Metabolismo de los Lípidos/genética , MicroARNs/genética , Receptores Nucleares Huérfanos/metabolismo , Animales , Aterosclerosis/genética , Aterosclerosis/patología , Colesterol/genética , Regulación de la Expresión Génica , Células Hep G2 , Hepatocitos/metabolismo , Hepatocitos/patología , Humanos , Receptores X del Hígado , Macrófagos/metabolismo , Ratones , Ratones Noqueados , Receptores Nucleares Huérfanos/genética , Transducción de Señal
12.
J Clin Invest ; 124(3): 1037-51, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24531544

RESUMEN

The nuclear bile acid receptor farnesoid X receptor (FXR) is an important transcriptional regulator of bile acid, lipid, and glucose metabolism. FXR is highly expressed in the liver and intestine and controls the synthesis and enterohepatic circulation of bile acids. However, little is known about FXR-associated proteins that contribute to metabolic regulation. Here, we performed a mass spectrometry-based search for FXR-interacting proteins in human hepatoma cells and identified AMPK as a coregulator of FXR. FXR interacted with the nutrient-sensitive kinase AMPK in the cytoplasm of target cells and was phosphorylated in its hinge domain. In cultured human and murine hepatocytes and enterocytes, pharmacological activation of AMPK inhibited FXR transcriptional activity and prevented FXR coactivator recruitment to promoters of FXR-regulated genes. Furthermore, treatment with AMPK activators, including the antidiabetic biguanide metformin, inhibited FXR agonist induction of FXR target genes in mouse liver and intestine. In a mouse model of intrahepatic cholestasis, metformin treatment induced FXR phosphorylation, perturbed bile acid homeostasis, and worsened liver injury. Together, our data indicate that AMPK directly phosphorylates and regulates FXR transcriptional activity to precipitate liver injury under conditions favoring cholestasis.


Asunto(s)
Adenilato Quinasa/metabolismo , Ácidos y Sales Biliares/biosíntesis , Homeostasis , Hipoglucemiantes/farmacología , Metformina/farmacología , Receptores Citoplasmáticos y Nucleares/metabolismo , Adenilato Quinasa/antagonistas & inhibidores , Secuencia de Aminoácidos , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacología , Animales , Transporte Biológico , Células CACO-2 , Colestasis Intrahepática/metabolismo , Colestasis Intrahepática/patología , Células Hep G2 , Humanos , Mucosa Intestinal/metabolismo , Intestinos/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Fosforilación , Regiones Promotoras Genéticas , Unión Proteica , Procesamiento Proteico-Postraduccional , Receptores Citoplasmáticos y Nucleares/química , Ribonucleótidos/farmacología , Transducción de Señal , Transactivadores/metabolismo , Transcripción Genética , Activación Transcripcional/efectos de los fármacos
13.
Int J Cardiol ; 172(1): 179-84, 2014 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-24456889

RESUMEN

BACKGROUND: Macrophages are crucial cells in the pathogenesis of atherosclerosis. Macrophages are plastic cells which can switch from a classical pro-inflammatory M1 to an alternative anti-inflammatory M2 macrophage phenotype, depending on the environmental stimuli. Because high-density lipoprotein (HDL) cholesterol levels are inversely correlated to cardiovascular disease and since HDL displays anti-inflammatory properties, we investigated whether HDL can affect alternative macrophage differentiation of primary human monocytes in the presence of interleukin (IL)-4, a M2 macrophage polarization driver, in vitro and ex vivo. METHODS AND RESULTS: M2 macrophages are highly responsive to HDL stimulation, since the expression of pentraxin 3 (PTX3), a well known HDL target gene, is induced by HDL more strongly in M2 macrophages than in control unpolarized resting macrophages (RM). As expected, the expression of M2 markers, such as Mannose Receptor (MR), CD200 Receptor (CD200R), Coagulation factor XIII A1 (F13A1), IL-1 receptor antagonist (IL-1RA) and IL10, was induced in IL-4 polarized M2 macrophages compared to RM. However, incubation with HDL added in vitro did not modulate the gene expression of M2 macrophage polarization markers. Moreover, monocytes isolated from subjects with genetically low HDL levels, carrying ABCA1 or LCAT mutations, differentiated ex vivo into M2 macrophages without any difference in the alternative macrophage marker expression profile. CONCLUSIONS: These in vitro and ex vivo results indicate that, contrary to mouse macrophages, HDL does not influence macrophage M2 polarization of human monocyte-derived macrophages. Thus, the anti-inflammatory properties of HDL in humans are probably not related to the enhancement of the M2 macrophage phenotype.


Asunto(s)
Aterosclerosis/inmunología , Polaridad Celular/inmunología , HDL-Colesterol/inmunología , Inflamación/inmunología , Monocitos/inmunología , Transportador 1 de Casete de Unión a ATP/genética , Transportador 1 de Casete de Unión a ATP/inmunología , Adulto , Antígenos de Superficie/genética , Antígenos de Superficie/inmunología , Aterosclerosis/genética , Aterosclerosis/patología , Biomarcadores , Células Cultivadas , HDL-Colesterol/farmacología , Factor XIII/genética , Factor XIII/inmunología , Femenino , Expresión Génica/inmunología , Humanos , Inflamación/genética , Inflamación/patología , Lectinas Tipo C/genética , Lectinas Tipo C/inmunología , Masculino , Receptor de Manosa , Lectinas de Unión a Manosa/genética , Lectinas de Unión a Manosa/inmunología , Persona de Mediana Edad , Monocitos/efectos de los fármacos , Monocitos/patología , Receptores de Orexina , Fenotipo , Fosfatidilcolina-Esterol O-Aciltransferasa/genética , Fosfatidilcolina-Esterol O-Aciltransferasa/inmunología , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/inmunología , Adulto Joven
14.
Circ Res ; 113(11): 1196-205, 2013 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-24036496

RESUMEN

RATIONALE: In atherosclerotic plaques, iron preferentially accumulates in macrophages where it can exert pro-oxidant activities. OBJECTIVE: The objective of this study was, first, to better characterize the iron distribution and metabolism in macrophage subpopulations in human atherosclerotic plaques and, second, to determine whether iron homeostasis is under the control of nuclear receptors, such as the liver X receptors (LXRs). METHODS AND RESULTS: Here we report that iron depots accumulate in human atherosclerotic plaque areas enriched in CD68 and mannose receptor (MR)-positive (CD68(+)MR(+)) alternative M2 macrophages. In vitro IL-4 polarization of human monocytes into M2 macrophages also resulted in a gene expression profile and phenotype favoring iron accumulation. However, M2 macrophages on iron exposure acquire a phenotype favoring iron release, through a strong increase in ferroportin expression, illustrated by a more avid oxidation of extracellular low-density lipoprotein by iron-loaded M2 macrophages. In line, in human atherosclerotic plaques, CD68(+)MR(+) macrophages accumulate oxidized lipids, which activate LXRα and LXRß, resulting in the induction of ABCA1, ABCG1, and apolipoprotein E expression. Moreover, in iron-loaded M2 macrophages, LXR activation induces nuclear factor erythroid 2-like 2 expression, thereby increasing ferroportin expression, which, together with a decrease of hepcidin mRNA levels, promotes iron export. CONCLUSIONS: These data identify a role for M2 macrophages in iron handling, a process regulated by LXR activation.


Asunto(s)
Hierro/metabolismo , Macrófagos/metabolismo , Macrófagos/patología , Receptores Nucleares Huérfanos/fisiología , Placa Aterosclerótica/metabolismo , Placa Aterosclerótica/patología , Transportador 1 de Casete de Unión a ATP/metabolismo , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 1 , Transportadoras de Casetes de Unión a ATP/metabolismo , Antígenos CD/metabolismo , Antígenos de Diferenciación Mielomonocítica/metabolismo , Apolipoproteínas E/metabolismo , Transporte Biológico/fisiología , Células Cultivadas , Homeostasis/fisiología , Humanos , Técnicas In Vitro , Lectinas Tipo C/metabolismo , Receptores X del Hígado , Receptor de Manosa , Lectinas de Unión a Manosa/metabolismo , Fenotipo , Receptores de Superficie Celular/metabolismo
15.
Eur Heart J ; 34(32): 2566-74, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22843443

RESUMEN

AIMS: Peroxisome proliferator-activated receptor (PPAR)-α is a transcription factor controlling lipid metabolism in liver, heart, muscle, and macrophages. Peroxisome proliferator-activated receptor-α activation increases plasma HDL cholesterol and exerts hypotriglyceridaemic actions via the liver. However, the intestine expresses PPAR-α, produces HDL and chylomicrons, and is exposed to diet-derived PPAR-α ligands. Therefore, we examined the effects of PPAR-α activation on intestinal lipid and lipoprotein metabolism. METHODS AND RESULTS: The impact of PPAR-α activation was evaluated in term of HDL-related gene expression in mice, ex vivo in human jejunal biopsies and in Caco-2/TC7 cells. Apolipoprotein-AI/HDL secretion, cholesterol esterification, and trafficking were also studied in vitro. In parallel to improving plasma lipid profiles and increasing liver and intestinal expression of fatty acid oxidation genes, treatment with the dual PPAR-α/δ ligand GFT505 resulted in a more pronounced increase in plasma HDL compared with fenofibrate in mice. GFT505, but not fenofibrate, increased the expression of HDL production genes such as apolipoprotein-AI and ATP-binding cassette A1 transporter in murine intestines. A similar increase was observed upon PPAR-α activation of human biopsies and Caco-2/TC7 cells. Additionally, HDL secretion by Caco-2/TC7 cells increased. Moreover, PPAR-α activation decreased the cholesterol esterification capacity of Caco-2/TC7 cells, modified cholesterol trafficking, and reduced apolipoprotein-B secretion. CONCLUSION: Peroxisome proliferator-activated receptor-α activation reduces cholesterol esterification, suppresses chylomicron, and increases HDL secretion by enterocytes. These results identify the intestine as a target organ of PPAR-α ligands with entero-hepatic tropism to reduce atherogenic dyslipidaemia.


Asunto(s)
Lipoproteínas HDL/metabolismo , PPAR alfa/fisiología , Animales , Apolipoproteínas B/metabolismo , Butiratos/farmacología , Células CACO-2 , Células Cultivadas , Chalconas/farmacología , Enterocitos/metabolismo , Esterificación/fisiología , Ácidos Grasos/metabolismo , Femenino , Humanos , Yeyuno/metabolismo , Ratones , Ratones Noqueados , PPAR alfa/antagonistas & inhibidores , Compuestos de Fenilurea/farmacología , Propionatos/farmacología
16.
Endocrinology ; 149(10): 5128-35, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18566121

RESUMEN

Liver X receptor-alpha (LXRalpha) and LXRbeta are ligand-activated transcription factors belonging to the nuclear receptor superfamily. They have been identified as key players in cholesterol homeostasis and lipid and glucose metabolism as well as immune and inflammatory responses. In the small intestine, LXRs have been shown not only to regulate cholesterol absorption and excretion but also to promote high-density lipoprotein biogenesis via the ATP-binding cassette A1 signaling pathway. Here, using gene expression assays, we identified PPARalpha as an intestine-specific LXR target gene. Chronic administration of LXR synthetic agonists led to a significant increase of PPARalpha mRNA levels in the small intestine but not in the liver. In addition, this specific PPARalpha gene up-regulation occurred in the duodenum, jejunum, and ileum in a dose-dependent manner and translated at the protein level as demonstrated by Western blot analysis. Furthermore, PPARalpha gene induction was completely abolished in LXR-deficient mice. Finally, the physiological relevance of LXR-mediated PPARalpha up-regulation in the small intestine was assessed in PPARalpha-deficient mice. Administration of a synthetic LXR agonist to wild-type mice led to the induction of several PPARalpha target genes including PDK4 and CPT1. Those effects were completely abolished in PPARalpha-deficient mice, demonstrating the biological relevance of this LXR-PPARalpha transcriptional cascade. Taken together, these results demonstrate that PPARalpha is an intestine-specific LXR target gene and suggest the existence of a transcriptional cross talk between those members of the nuclear receptor superfamily.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Intestinos/fisiología , PPAR alfa/genética , Receptores Citoplasmáticos y Nucleares/metabolismo , Animales , Benzoatos/farmacología , Bencilaminas/farmacología , Proteínas de Unión al ADN/agonistas , Proteínas de Unión al ADN/genética , Regulación de la Expresión Génica/fisiología , Homeostasis/fisiología , Hidrocarburos Fluorados , Metabolismo de los Lípidos/fisiología , Hígado/fisiología , Receptores X del Hígado , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Especificidad de Órganos , Receptores Nucleares Huérfanos , PPAR alfa/metabolismo , ARN Mensajero/metabolismo , Receptor Cross-Talk/fisiología , Receptores Citoplasmáticos y Nucleares/agonistas , Receptores Citoplasmáticos y Nucleares/genética , Sulfonamidas/farmacología , Transcripción Genética/fisiología , Activación Transcripcional
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