Ricardo Rodríguez-Calvo

Hospital de la Santa Creu i Sant Pau, Barcino, Catalonia, Spain

Are you Ricardo Rodríguez-Calvo?

Claim your profile

Publications (39)148.09 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Lysyl oxidase (LOX) is an extracellular matrix-modifying enzyme that could play a critical role in vascular remodelling. We have developed a transgenic mouse model that over-expresses LOX in vascular smooth muscle cells (VSMC) to clarify whether LOX could regulate VSMC phenotype and vascular remodelling.
    Cardiovascular research. 07/2014; 103(suppl 1):S132.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Lysyl oxidase (LOX) is an extracellular matrix-modifying enzyme that seems to play a critical role in vascular remodelling. However, the lack of viable LOX-deficient animal models has been an obstacle to deep in LOX biology. In this study we have developed a transgenic mouse model that over-expresses LOX in vascular smooth muscle cells (VSMC) to clarify whether LOX could regulate VSMC phenotype and vascular remodelling. The SM22α proximal promoter drove the expression of a transgene containing the human LOX cDNA. Two stable transgenic lines, phenotypically indistinguishable, were generated by conventional methods (TgLOX). Transgene expression followed the expected SMC-specific pattern. In TgLOX mice, real-time PCR and immunohistochemistry evidenced a strong expression of LOX in the media from aorta and carotid arteries, coincident with a higher proportion of mature collagen. VSMC isolated from TgLOX mice expressed high levels of LOX pro-enzyme, which was properly secreted and processed into mature and bioactive LOX. Interestingly, cell proliferation was significantly reduced in cells from TgLOX mice. Transgenic VSMC also exhibited low levels of Myh10 (marker of SMC phenotypic switching), PCNA (marker of cell proliferation) and MCP-1, and a weak activation of Akt and ERK1/2 in response to mitogenic stimuli. Accordingly, neointimal thickening induced by carotid artery ligation was attenuated in TgLOX mice that also displayed a reduction in PCNA and MCP-1 immunostaining. Our results give evidence that LOX plays a critical role in vascular remodelling. We have developed a new animal model to study the role of LOX in vascular biology.
    Thrombosis and Haemostasis 05/2014; · 5.76 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Previous studies have shown that the loss of NOR-1 function modulates the activation of vascular smooth muscle cells (VSMC). In this study we use a mouse that over-expresses human NOR-1 in VSMC to analyze the effect of a gain of NOR-1 function on the activation of VSMC and in the hyperplasia of the intima induced by hemodynamic stress. To generate the transgenic animal the human NOR-1 cDNA was placed under the control of the SM22α promoter. The expression of NOR-1 was analyzed by real time PCR, Western blot, immunohistochemistry and immunocitochemistry, and NOR-1 functionality was evaluated by luciferase activity assays. The incorporation of tritiated thymidine was determined as a cell proliferation index. The left carotid artery was ligated, and cross-sections were subjected to morphometric and immunostaining analysis. The transgenic mouse exhibited significant levels of human NOR-1 in aorta and carotid arteries. In aortic VSMC from transgenic mice an increase in the transcriptional activity of ciclin D2 was detected, as well as higher proliferative rates and increased levels of the marker Myh10. In these animals, carotid artery ligation induced a greater neointimal formation and a higher stenotic grade than in wild-type animals, in accordance with the labelling detected for Myh10 and phosphorylated Histone H3. These results reinforce the role of NOR-1 in VSMC proliferation and in vascular remodelling, and allow us to propose this model as a useful tool to study the involvement of NOR-1 in vascular function and in vascular diseases such as atherosclerosis and restenosis.
    Clinica e Investigacion en Arteriosclerosis 03/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Introduction Previous studies have shown that the loss of NOR-1 function modulates the activation of vascular smooth muscle cells (VSMC). In this study we use a mouse that over-expresses human NOR-1 in VSMC to analyze the effect of a gain of NOR-1 function on the activation of VSMC and in the hyperplasia of the intima induced by hemodynamic stress. Methods To generate the transgenic animal the human NOR-1 cDNA was placed under the control of the SM22α promoter. The expression of NOR-1 was analyzed by real time PCR, Western blot, immunohistochemistry and immunocitochemistry, and NOR-1 functionality was evaluated by luciferase activity assays. The incorporation of tritiated thymidine was determined as a cell proliferation index. The left carotid artery was ligated, and cross-sections were subjected to morphometric and immunostaining analysis. Results The transgenic mouse exhibited significant levels of human NOR-1 in aorta and carotid arteries. In aortic VSMC from transgenic mice an increase in the transcriptional activity of ciclin D2 was detected, as well as higher proliferative rates and increased levels of the marker Myh10. In these animals, carotid artery ligation induced a greater neointimal formation and a higher stenotic grade than in wild-type animals, in accordance with the labelling detected for Myh10 and phosphorylated Histone H3. Conclusions These results reinforce the role of NOR-1 in VSMC proliferation and in vascular remodelling, and allow us to propose this model as a useful tool to study the involvement of NOR-1 in vascular function and in vascular diseases such as atherosclerosis and restenosis.
    Clínica e Investigación en Arteriosclerosis. 01/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: OBJECTIVE: Atherosclerosis and restenosis are multifactorial diseases associated with abnormal vascular smooth muscle cell (VSMC) proliferation. Nuclear factor-Y (NF-Y) plays a major role in transcriptional activation of CYCLIN B1 (CCNB1), a key positive regulator of cell proliferation and neointimal thickening. Here, we investigated the role of NF-Y in occlusive vascular disease.Approach and Results-We performed molecular and expression studies in cultured cells, animal models, and human tissues. We find upregulation of NF-Y and cyclin B1 expression in proliferative regions of murine atherosclerotic plaques and mechanically induced lesions, which correlates with higher binding of NF-Y to target sequences in the CCNB1 promoter. NF-YA expression in neointimal lesions is detected in VSMCs, macrophages, and endothelial cells. Platelet-derived growth factor-BB, a main inductor of VSMC growth and neointima development, induces the recruitment of NF-Y to the CCNB1 promoter and augments both CCNB1 mRNA expression and cell proliferation through extracellular signal-regulated kinase 1/2 and Akt activation in rat and human VSMCs. Moreover, adenovirus-mediated overexpression of a NF-YA-dominant negative mutant inhibits platelet-derived growth factor-BB-induced CCNB1 expression and VSMC proliferation in vitro and neointimal lesion formation in a mouse model of femoral artery injury. We also detect NF-Y expression and DNA-binding activity in human neointimal lesions. CONCLUSIONS: Our results identify NF-Y as a key downstream effector of the platelet-derived growth factor-BB-dependent mitogenic pathway that is activated in experimental and human vasculoproliferative diseases. They also identify NF-Y inhibition as a novel and attractive strategy for the local treatment of neointimal formation induced by vessel denudation.
    Arteriosclerosis Thrombosis and Vascular Biology 02/2013; · 6.34 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background and Objective We have previously shown that NOR-1 (NR4A3) modulates the proliferation and survival of vascular cells in culture. However, in genetically modified animal models somewhat conflicting results have been reported concerning the involvement of NOR-1 in neotintimal formation after vascular injury. The aim of this study was to generate a transgenic mouse model over-expressing NOR-1 in smooth muscle cells (SMC) and assess the consequence of a gain-of-function of this receptor on intimal hyperplasia after vascular injury.Methods and ResultsThe transgene construct (SM22-NOR1) was prepared by ligating the full-length human NOR-1 cDNA (hNOR-1) and a mouse SM22α minimal promoter able to drive NOR-1 expression to SMC. Two founders were generated and two stable transgenic mouse lines (TgNOR-1) were established by backcrossing the transgene-carrying founders with C57BL/6J mice. Real-time PCR and immunohistochemistry confirmed that hNOR-1 was mainly targeted to vascular beds such as aorta and carotid arteries, and was similar in both transgenic lines. Vascular SMC from transgenic animals exhibit increased NOR-1 transcriptional activity (assessed by EMSA and luciferase assays), increased mitogenic activity (determined by [(3)H]-thymidine incorporation; 1.58-fold induction, p<0.001) and increased expression of embryonic smooth muscle myosin heavy chain (SMemb) than wild-type cells from control littermates. Using the carotid artery ligation model we show that neointima formation was increased in transgenic versus wild-type mice (2.36-fold induction, p<0.01).Conclusions Our in vivo data support a role for NOR-1 in VSMC proliferation and vascular remodelling. This NOR-1 transgenic mouse could be a useful model to study fibroproliferative vascular diseases.
    Human Molecular Genetics 02/2013; · 7.69 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Our aim was to analyze the regulation of CC Chemokine ligand 20 (CCL20) by LDL in human vascular smooth muscle cells (VSMC). In asymptomatic subjects, circulating CCL20 levels were higher in patients with hypercholesterolemia (18.5±3.2 versus 9.1±1.3 pg/mL; P<0.01). LDL induced the expression of CCL20 in VSMC in a dose- and time-dependent manner. Increased levels of CCL20 secreted by LDL-treated VSMC significantly induced human lymphocyte migration, an effect reduced by CCL20 silencing. The upregulation of CCL20 by LDL was dependent on the activation of kinase signaling pathways and NF-κB. By site-directed mutagenesis, electrophoretic mobility shift assay, and chromatin immunoprecipitation, we identified a NF-κB site (-80/-71) in CCL20 promoter critical for LDL responsiveness. Lysophosphatidic acid mimicked the upregulation of CCL20 induced by LDL, and minimal oxidation of LDL increased the ability of LDL to induce CCL20 through a mechanism that involves lysophosphatidic acid receptors. CCL20 was overexpressed in atherosclerotic lesions from coronary artery patients, colocalizing with VSMC. CCL20 was detected in conditioned media from healthy human aorta and its levels were significantly higher in secretomes from carotid endarterectomy specimens. This study identifies CCL20 in atherosclerotic lesions and recognizes this chemokine as a mediator highly sensitive to the inflammatory response elicited by LDL.
    Arteriosclerosis Thrombosis and Vascular Biology 08/2011; 31(11):2733-41. · 6.34 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Type II interleukin-1 receptor (IL-1R2) is a non-signaling decoy receptor that negatively regulates the activity of interleukin-1 (IL-1), a pro-inflammatory cytokine involved in atherogenesis. In this article we assessed the relevance of IL-1R2 in atherosclerosis by studying its expression in monocytes from hyperlipidemic patients, in THP-1 macrophages exposed to lipoproteins and in human atherosclerotic lesions. Our results showed that the mRNA and protein expression of IL-1R2 was reduced in monocytes from patients with familial combined hyperlipidemia (-30%, p<0.05). THP-1 macrophages incubated with increasing concentrations of acetylated low density (ac-LDL) and very low density (VLDL) lipoproteins also exhibit a decrease in IL-1R2 mRNA and protein levels. Pre-incubation with agents that block intracellular accumulation of lipids prevents the decrease in IL-1R2 mRNA caused by lipoproteins. Lipoproteins also prevented the increase in IL-1R1 and IL-1R2 caused by a 4-h stimulation with LPS and reduced protein expression of total and phosphorylated IL-1 receptor-associated kinase-1. Finally, IL-1R2 expression in human atherosclerotic vessels was markedly lower than in non-atherosclerotic arteries (-80%, p<0.0005). Overall, our results suggest that under atherogenic conditions, there is a decrease in IL-1R2 expression in monocytes/macrophages and in the vascular wall that may facilitate IL-1 signaling.
    Biochimica et Biophysica Acta 06/2011; 1811(9):556-63. · 4.66 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: It has been suggested that interleukin (IL)-6 is one of the mediators linking obesity-derived chronic inflammation with insulin resistance through activation of STAT3, with subsequent upregulation of suppressor of cytokine signaling 3 (SOCS3). We evaluated whether peroxisome proliferator-activated receptor (PPAR)-β/-δ prevented activation of the IL-6-STAT3-SOCS3 pathway and insulin resistance in adipocytes. Adipocytes and white adipose tissue from wild-type and PPAR-β/-δ-null mice were used to evaluate the effect of PPAR-β/-δ on the IL-6-STAT3-SOCS3 pathway. First, we observed that the PPAR-β/-δ agonist GW501516 prevented both IL-6-dependent reduction in insulin-stimulated Akt phosphorylation and glucose uptake in adipocytes. In addition, this drug treatment abolished IL-6-induced SOCS3 expression in differentiated 3T3-L1 adipocytes. This effect was associated with the capacity of the drug to prevent IL-6-induced STAT3 phosphorylation on Tyr(705) and Ser(727) residues in vitro and in vivo. Moreover, GW501516 prevented IL-6-dependent induction of extracellular signal-related kinase (ERK)1/2, a serine-threonine-protein kinase involved in serine STAT3 phosphorylation. Furthermore, in white adipose tissue from PPAR-β/-δ-null mice, STAT3 phosphorylation (Tyr(705) and Ser(727)), STAT3 DNA-binding activity, and SOCS3 protein levels were higher than in wild-type mice. Several steps in STAT3 activation require its association with heat shock protein 90 (Hsp90), which was prevented by GW501516 as revealed in immunoprecipitation studies. Consistent with this finding, the STAT3-Hsp90 association was enhanced in white adipose tissue from PPAR-β/-δ-null mice compared with wild-type mice. Collectively, our findings indicate that PPAR-β/-δ activation prevents IL-6-induced STAT3 activation by inhibiting ERK1/2 and preventing the STAT3-Hsp90 association, an effect that may contribute to the prevention of cytokine-induced insulin resistance in adipocytes.
    Diabetes 05/2011; 60(7):1990-9. · 7.90 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To assess whether angiotensin II (Ang II) modulates key enzymes of the cyclooxygenase (COX)-2/prostanoid pathway, including prostaglandin E synthase-1 (mPGES-1) and prostacyclin synthase (PGIS) in rat aortic adventitial fibroblasts in the presence or absence of an inflammatory stimulus [interleukin (IL)-1β]. Fibroblasts stimulated with IL-1β (10 ng/ml, 24 h) and/or Ang II (0.1 μmol/l, 24 h) were used. IL-1β up-regulated COX-2 and mPGES-1 (protein and mRNA) and increased PGI2 and PGE2 release, without altering PGIS protein expression. Ang II did modify neither COX-2 and mPGES-1 expression nor prostanoid levels, but it induced PGIS expression. Interestingly, Ang II further enhanced IL-1β-induced COX-2 expression and PGI2 release and concomitantly reduced IL-1β-induced mPGES-1 expression. The AT1 receptor antagonist losartan prevented the effects of Ang II on IL-1β-induced COX-2 or mPGES-1 expression. IL-1β activated p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK)1/2 pathways, and coincubation with Ang II resulted in a higher and more sustained phosphorylation of both MAPK. Inhibition of either p38 MAPK (SB203580) or ERK1/2 (PD98059) reduced COX-2 and mPGES-1 expression in cells treated with IL-1β or the combination of IL-1β and Ang II. Ang II did not modify COX-2 transcriptional activity but increased COX-2 mRNA stability in IL-1β-treated cells; by contrast, it increased PGIS mRNA levels through a transcriptional mechanism. Ang II differentially modulates key enzymes involved in prostanoid biosynthesis thereby altering the balance between PGI2/PGE2 in vascular cells exposed to inflammatory stimuli.
    Journal of Hypertension 03/2011; 29(3):529-36. · 4.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Metabolic syndrome-associated dyslipidemia is mainly initiated by hepatic overproduction of the plasma lipoproteins carrying triglycerides. Here we examined the effects of the peroxisome proliferator-activated receptors (PPAR)-β/δ activator GW501516 on high-fat diet (HFD)-induced hypertriglyceridemia and hepatic fatty acid oxidation. Exposure to the HFD caused hypertriglyceridemia that was accompanied by reduced hepatic mRNA levels of PPAR-γ coactivator 1 (PGC-1)-α and lipin 1, and these effects were prevented by GW501516 treatment. GW501516 treatment also increased nuclear lipin 1 protein levels, leading to amplification in the PGC-1α-PPARα signaling system, as demonstrated by the increase in PPARα levels and PPARα-DNA binding activity and the increased expression of PPARα-target genes involved in fatty acid oxidation. These effects of GW501516 were accompanied by an increase in plasma β-hydroxybutyrate levels, demonstrating enhanced hepatic fatty acid oxidation. Moreover, GW501516 increased the levels of the hepatic endogenous ligand for PPARα, 16:0/18:1-phosphatidilcholine and markedly enhanced the expression of the hepatic Vldl receptor. Interestingly, GW501516 prevented the reduction in AMP-activated protein kinase (AMPK) phosphorylation and the increase in phosphorylated levels of ERK1/2 caused by HFD. In addition, our data indicate that the activation of AMPK after GW501516 treatment in mice fed HFD might be the result of an increase in the AMP to ATP ratio in hepatocytes. These findings indicate that the hypotriglyceridemic effect of GW501516 in HFD-fed mice is accompanied by an increase in phospho-AMPK levels and the amplification of the PGC-1α-lipin 1-PPARα pathway.
    Endocrinology 03/2011; 152(5):1848-59. · 4.72 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Hypoxia modulates gene expression and affects multiple aspects of endothelial cell biology. Fibulin-5 (FBLN5) is an extracellular matrix protein essential for elastic fiber assembly and vasculogenesis that participates in vascular remodeling and controls endothelial cell adhesion, motility, and proliferation. In this context, we aimed to analyze FBLN5 regulation by hypoxia in endothelial cells. Hypoxia (1% O(2)) increased FBLN5 mRNA levels in endothelial cells in a time-dependent manner. Maximal induction (∼2.5-fold) was achieved after 24 h of hypoxia. This effect paralleled an increase in both intracellular and extracellular FBLN5 protein levels. The increase in FBLN5 mRNA levels observed in hypoxic cells was blocked by inhibitors of the PI3K/Akt/mTOR pathway (LY294002 and rapamycin) and mimicked by dimethyl oxal glycine, which prevents proline hydroxylase-mediated degradation of HIF-1α. Silencing of HIF-1α completely prevented hypoxia-induced FBLN5 up-regulation. Accordingly, both hypoxia and HIF-1α overexpression increased FBLN5 transcriptional activity. Serial promoter deletion and mutagenesis studies revealed the involvement of a putative hypoxia response element (HRE) located at -78 bp. In fact, EMSA and ChIP assays demonstrated increased HIF-1 binding to this site in hypoxic cells. Interestingly, the rate of endothelial cells undergoing apoptosis in cultures exposed to hypoxia increased in FBLN5 knockdown cells, suggesting that hypoxia-induced FBLN5 expression contributes to preserve cell survival. These results provide evidence that HIF-1 signaling underlies the increase of FBLN5 expression elicited by hypoxia in endothelial cells and suggest that FBLN5 induction could be involved in the adaptive survival response of endothelial cells to hypoxia.
    Journal of Biological Chemistry 12/2010; 286(9):7093-103. · 4.65 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Owing to its high fat content, the classical Western diet has a range of adverse effects on the heart, including enhanced inflammation, hypertrophy, and contractile dysfunction. Proinflammatory factors secreted by cardiac cells, which are under the transcriptional control of nuclear factor-κB (NF-κB), may contribute to heart failure and dilated cardiomyopathy. The underlying mechanisms are complex, since they are linked to systemic metabolic abnormalities and changes in cardiomyocyte phenotype. Peroxisome proliferator-activated receptors (PPARs) are transcription factors that regulate metabolism and are capable of limiting myocardial inflammation and hypertrophy via inhibition of NF-κB. Since PPARβ/δ is the most prevalent PPAR isoform in the heart, we analyzed the effects of the PPARβ/δ agonist GW501516 on inflammatory parameters. A high-fat diet induced the expression of tumor necrosis factor-α, monocyte chemoattractant protein-1, and interleukin-6, and enhanced the activity of NF-κB in the heart of mice. GW501516 abrogated this enhanced proinflammatory profile. Similar results were obtained when human cardiac AC16 cells exposed to palmitate were coincubated with GW501516. PPARβ/δ activation by GW501516 enhanced the physical interaction between PPARβ/δ and p65, which suggests that this mechanism may also interfere NF-κB transactivation capacity in the heart. GW501516-induced PPARβ/δ activation can attenuate the inflammatory response induced in human cardiac AC16 cells exposed to the saturated fatty acid palmitate and in mice fed a high-fat diet. This is relevant, especially taking into account that PPARβ/δ has been postulated as a potential target in the treatment of obesity and the insulin resistance state.
    Biochimica et Biophysica Acta 11/2010; 1811(2):59-67. · 4.66 Impact Factor
  • Atherosclerosis Supplements - ATHEROSCLER SUPPL. 01/2010; 11(2):94-94.
  • Atherosclerosis Supplements - ATHEROSCLER SUPPL. 01/2010; 11(2):93-94.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Metabolic syndrome is defined as the clustering of multiple metabolic abnormalities, including abdominal obesity, dyslipidemia (high serum triglycerides and low serum HDL-cholesterol levels), glucose intolerance and hypertension. The pathophysiology underlying metabolic syndrome involves a complex interaction of crucial factors, but two of these, insulin resistance and obesity (especially visceral obesity), play a major role. The nuclear receptors Peroxisome Proliferator-Activated Receptors (PPAR)alpha and PPARgamma are therapeutic targets for hypertriglyceridemia and insulin resistance, respectively. Evidence is now emerging that the PPARbeta/delta; isotype is a potential pharmacological target for the treatment of disorders associated with metabolic syndrome. PPARbeta/delta; activation increases lipid catabolism in skeletal muscle, heart and adipose tissue and improves the serum lipid profile and insulin sensitivity in several animal models. In addition, PPARbeta/delta; ligands prevent weight gain and suppress macrophage-derived inflammation. These data are promising and indicate that PPARbeta/delta; ligands may become a therapeutic option for the treatment of metabolic syndrome. However, clinical trials in humans assessing the efficacy and safety of these drugs should confirm these promising perspectives in the treatment of the metabolic syndrome.
    Current Molecular Pharmacology 01/2010; 2(1):46-55.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Thrombin is a multifunctional serine protease that promotes vascular proinflammatory responses whose effect on endothelial MMP-10 expression has not previously been evaluated. Thrombin induced endothelial MMP-10 mRNA and protein levels, through a protease-activated receptor-1 (PAR-1)-dependent mechanism, in a dose- and time-dependent manner. This effect was mimicked by a PAR-1 agonist peptide (TRAP-1) and antagonized by an anti-PAR-1 blocking antibody. MMP-10 induction was dependent on extracellular regulated kinase1/2 (ERK1/2) and c-jun N-terminal kinase (JNK) pathways. By serial deletion analysis, site-directed mutagenesis and electrophoretic mobility shift assay an AP-1 site in the proximal region of MMP-10 promoter was found to be critical for thrombin-induced MMP-10 transcriptional activity. Thrombin and TRAP-1 upregulated MMP-10 in murine endothelial cells in culture and in vivo in mouse aorta. This effect of thrombin was not observed in PAR-1-deficient mice. Interestingly, circulating MMP-10 levels (P<0.01) were augmented in patients with endothelial activation associated with high (disseminated intravascular coagulation) and moderate (previous acute myocardial infarction) systemic thrombin generation. Thrombin induces MMP-10 through a PAR-1-dependent mechanism mediated by ERK1/2, JNK, and AP-1 activation. Endothelial MMP-10 upregulation could be regarded as a new proinflammatory effect of thrombin whose pathological consequences in thrombin-related disorders and plaque stability deserve further investigation.
    Arteriosclerosis Thrombosis and Vascular Biology 09/2009; 29(12):2109-16. · 6.34 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Introduction and objective Insulin resistance is associated with a low-grade systemic inflammatory response characterized by NF-κB activation and pro-inflammatory cytokine production from white adipose tissue. Recently PPARβ/δ has been proposed as a potential treatment for insulin resistance. However, it is presently unknown whether PPARβ/δ activation prevents this process in adipocytes. Methods and results PPARβ/δ activation by GW501516 blocked LPS-induced IL-6 expression and secretion by 3T3-L1 adipocytes. This effect was associated with the capacity of GW501516 to prevent LPS-induced NF-κB activation. In addition, IL-6 expression and NF-κB DNA-binding activity was higher in white adipose tissue from PPARβ/δ-null mice than in wild-type mice, fact that suggests that this receptor regulates NF-κB activation and its target genes. Since the ERK1/2 pathway has been involved in NF-κB activation, we explored the effect of PPARβ/δ activation on this pathway. GW501516 treatment prevented ERK1/2-phosphorylation by LPS, whereas white adipose tissue from PPARβ/δ-null mice showed increased phospho-ERK1/2 levels. Conclusions These findings indicate that PPARβ/δ activation blocks enhanced cytokine production in adipocytes by preventing NF-κB activation via ERK1/2. This PPARβ/δ effect may contribute to prevent insulin resistance.
    Clínica e Investigación en Arteriosclerosis. 06/2009; 21(3).
  • [Show abstract] [Hide abstract]
    ABSTRACT: The endothelium regulates vascular homeostasis and is responsible for angiogenesis, a process mediated by the sprouting of endothelial cells from pre-existing vessels. Several lines of evidence indicate that endothelial progenitor cells (EPCs) also play a role in adult neovascularization as well as in the maintenance of endothelial integrity and function. Hypercholesterolemia is associated with increased cardiovascular risk by inducing a cascade of events leading to endothelial dysfunction and injury. Growing evidence indicates that low-density lipoproteins (LDLs) impair endothelial reparative processes by inducing endothelial cell apoptosis but also by reducing the number and function of EPCs. The involvement of LDLs in mechanisms associated with vascular repair and neovascularization is also suggested by data from studies using lipid-lowering drugs (statins). This review is focused on the central role of the cholesterol pathway in the biology of the endothelium and EPCs.
    Pathobiology 02/2009; 76(1):11-22. · 1.95 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Introduction and objective: Insulin resistance is associated with a low-grade systemic inflammatory response characterized by NF-kB activation and pro-inflammatory cytokine production from white adipose tissue. Recently PPARß/d has been proposed as a potential treatment for insulin resistance. However, it is presently unknown whether PPARß/d activation prevents this process in adipocytes. Methods and results: PPARß/d activation by GW501516 blocked LPS-induced IL-6 expression and secretion by 3T3-L1 adipocytes. This effect was associated with the capacity of GW501516 to prevent LPS-induced NF-kB activation. In addition, IL-6 expression and NF-kB DNA-binding activity was higher in white adipose tissue from PPARß/d-null mice than in wild-type mice, fact that suggests that this receptor regulates NF-kB activation and its target genes. Since the ERK1/2 pathway has been involved in NF-kB activation, we explored the effect of PPARß/d activation on this pathway. GW501516 treatment prevented ERK1/2-phosphorylation by LPS, whereas white adipose tissue from PPARß/d-null mice showed increased phospho-ERK1/2 levels. Conclusions: These findings indicate that PPARß/d activation blocks enhanced cytokine production in adipocytes by preventing NF-kB activation via ERK1/2. This PPARß/d effect may contribute to prevent insulin resistance. Introducción y objetivo: La resistencia a la insulina se relaciona con la presencia de un proceso inflamatorio de baja intensidad, caracterizado por la activación crónica del factor nuclear kappa B (NF-kB) y la producción de citocinas proinflamatorias en tejido adiposo blanco. Recientemente, se ha propuesto que el receptor activado por proliferadores peroxisómicos ß/d (PPARß/d) puede llegar a convertirse en una diana para el tratamiento de la resistencia a la insulina. Sin embargo, se desconoce si la activación de este receptor nuclear previene el proceso inflamatorio en adipocitos. Métodos y resultados: La activación de PPARß/d por un ligando específico, GW501516, evitó el aumento en la expresión y la secreción de interleucina (IL) 6 inducida por lipopolisacárido (LPS) en adipocitos 3T3-L1. Este efecto se asoció con la capacidad del agonista de PPARß/d para inhibir la activación del NF-kB inducida por LPS. Por otro lado, la expresión de IL-6 y la actividad del NF-?B estaban incrementadas en el tejido adiposo de ratones PPARß/d-/-, en comparación con ratones wild-type, hecho que indica que este receptor regula la activación de NF-?B y de sus genes diana. Puesto que se ha relacionado la activación de la vía ERK1/2 con la activación de NF-kB, determinamos el efecto de PPARß/d en la activación de esta vía. El tratamiento con GW501516 evitó la fosforilación de ERK1/2 inducida por LPS, mientras que el tejido adiposo blanco de ratones PPARß/d-/- mostró un incremento considerable en los valores de fosforilación de esta cinasa. Conclusiones: Estos resultados parecen indicar que la activación de PPARß/d bloquea el incremento de la producción de citocinas inflamatorias en adipocitos mediante la prevención de la activación de NF-kB por ERK1/2. Esta acción de PPARß/d puede contribuir a prevenir la resistencia a la insulina.
    Clínica e investigación en arteriosclerosis, ISSN 1578-187, Vol. 21, Nº. 3, 2009, pags. 97-105. 01/2009;

Publication Stats

490 Citations
148.09 Total Impact Points

Institutions

  • 2009–2014
    • Hospital de la Santa Creu i Sant Pau
      Barcino, Catalonia, Spain
  • 2011
    • ICCC Catalan Institute of Cardiovascular Sciences
      Barcino, Catalonia, Spain
  • 2005–2011
    • University of Barcelona
      • • Departament de Farmacologia i Química Terapèutica
      • • Faculty of Pharmacy
      Barcelona, Catalonia, Spain
  • 2008–2010
    • Instituto de Salud Carlos III
      • CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM)
      Madrid, Madrid, Spain