José Hermida

Universidad de Navarra, Pamplona, Navarre, Spain

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Publications (55)239.75 Total impact

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    ABSTRACT: Background The endothelial protein C receptor (EPCR) must be bound to a molecule of phosphatidylcholine (PCh) to be fully functional, i.e. to interact with protein C/activated protein C (APC) properly. PCh can be replaced with other lipids like lysophosphatidylcholine or platelet activating factor by the action of secretory group V phospholipase A2 (sPLA2-V), an enzyme upregulated in a variety of inflammatory conditions. Studies in purified systems demonstrated that the substitution of PCh notably impairs EPCR function in a process called EPCR encryption.Objectives We wanted to analyze if sPLA2-V was able to regulate EPCR dependent protein C activation in vivo, and its impact over thrombosis and hemostatic system.Methods Mice were transfected with secretory group V phospholipase by hydrodynamic gene delivery. The effects over thrombosis were studied with the laser carotid artery occlusion model and APC generation capacity was measured by ELISA. Global haemostasis was analyzed by thromboelastometry.ResultsWe confirm that sPLA2-V overexpression in mice significantly decreases their ability to generate APC. Furthermore, a murine carotid artery laser thrombosis model reveals that higher sPLA2-V levels are directly associated with faster artery thrombosis times.ConclusionssPLA2-V plays a thrombogenic role by impairing the ability of EPCR to promote protein C activation.This article is protected by copyright. All rights reserved.
    Journal of Thrombosis and Haemostasis 07/2014; · 6.08 Impact Factor
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    ABSTRACT: In the last few years, the number of anticoagulated patients has significantly increased and, as a consequence, so have hemorrhagic complications due to this therapy. We analyzed gastrointestinal (GI) bleeding because it is the most frequent type of major bleeding in these patients, and we hypothesized that they would have lesions responsible for GI bleeding regardless of the intensity of anticoagulation, although excessively anticoagulated patients would have more serious hemorrhages. To study the characteristics of anticoagulated patients with GI bleeding and the relationship between the degree of anticoagulation and a finding of causative lesions and bleeding severity. We prospectively studied 96 patients, all anticoagulated with acenocoumarol and consecutively admitted to hospital between 01/01/2003 and 09/30/2005 because of acute GI bleeding. We excluded patients with severe liver disease, as well as nine patients with incomplete details. The incidence of GI bleeding requiring hospitalization was 19.6 cases/100,000 inhabitants-year. In 90% of patients, we found a causative (85% of upper GI bleeding and 50% of lower GI bleeding) or potentially causative lesion, and 30% of them required endoscopic treatment, without differences depending on the intensity of anticoagulation. No relationship was found between the type of lesions observed and the degree of anticoagulation in these patients. Patients who received more intense anticoagulation therapy had more severe hemorrhages (23% of patients with an INR ≥4 had a life-threatening bleed versus only 4% of patients with INR <4). We found an incidence of 20 severe GI bleeding episodes in anticoagulated patients per 100,000 inhabitants-year, with no difference in localization or in the frequency of causative lesions depending on the intensity of anticoagulation. Patients receiving more intense anticoagulation had more severe GI bleeding episodes.
    Gastroenterología y Hepatología 02/2014; · 0.57 Impact Factor
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    ABSTRACT: In the last few years, the number of anticoagulated patients has significantly increased and, as a consequence, so have hemorrhagic complications due to this therapy. We analyzed gastrointestinal (GI) bleeding because it is the most frequent type of major bleeding in these patients, and we hypothesized that they would have lesions responsible for GI bleeding regardless of the intensity of anticoagulation, although excessively anticoagulated patients would have more serious hemorrhages. Objectives To study the characteristics of anticoagulated patients with GI bleeding and the relationship between the degree of anticoagulation and a finding of causative lesions and bleeding severity. Patients and methods We prospectively studied 96 patients, all anticoagulated with acenocoumarol and consecutively admitted to hospital between 01/01/2003 and 09/30/2005 because of acute GI bleeding. We excluded patients with severe liver disease, as well as nine patients with incomplete details. Results The incidence of GI bleeding requiring hospitalization was 19.6 cases/100,000 inhabitants-year. In 90% of patients, we found a causative (85% of upper GI bleeding and 50% of lower GI bleeding) or potentially causative lesion, and 30% of them required endoscopic treatment, without differences depending on the intensity of anticoagulation. No relationship was found between the type of lesions observed and the degree of anticoagulation in these patients. Patients who received more intense anticoagulation therapy had more severe hemorrhages (23% of patients with an INR ≥ 4 had a life-threatening bleed versus only 4% of patients with INR < 4). Conclusions We found an incidence of 20 severe GI bleeding episodes in anticoagulated patients per 100,000 inhabitants-year, with no difference in localization or in the frequency of causative lesions depending on the intensity of anticoagulation. Patients receiving more intense anticoagulation had more severe GI bleeding episodes.
    Gastroenterología y Hepatología. 01/2014;
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    ABSTRACT: The role of metalloproteinase-10 (MMP-10) in type 1 diabetes is not known. We hypothesise that it plays a role in the onset and progression of diabetic nephropathy and retinopathy. Serum MMP-10 levels from 269 patients with type 1 diabetes were measured, and their association with microvascular complications was analysed. We also studied whether knocking out the Mmp10 gene influenced the extent of renal injury and retinal damage in a streptozotocin-induced diabetic mouse model. The risk of nephropathy and proliferative retinopathy associated with the highest vs the lowest MMP-10 tertile was increased three to four times independently of the classical risk factors. Accordingly, renal function and morphology were better preserved in diabetic Mmp10 (-⁄-) mice than in their Mmp10 (+/+) counterparts. There were more kidney-infiltrating macrophages in diabetic Mmp10(+/+) mice, suggesting that MMP-10 contributes to the inflammatory response leading to microvascular complications. The loss of neuronal cells in the retinas of diabetic Mmp10 (+/+) mice was higher than in Mmp10 (-⁄-) mice. Retinal inflammation was decreased in Mmp10 (-⁄-) mice, as indicated by their reduced retinal caspase-1 levels. MMP-10 is involved in the development of microvascular complications in type 1 diabetes and emerges as a potential therapeutic target for slowing down the evolution of diabetic nephropathy and retinopathy.
    Diabetologia 09/2013; · 6.49 Impact Factor
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    ABSTRACT: Many cancer patients are at high risk of venous thromboembolism (VTE) during hospitalisation; nevertheless, thromboprophylaxis is frequently underused. Electronic alerts (e-alerts) have been associated with improvement in thromboprophylaxis use and a reduction of the incidence of VTE, both during hospitalisation and after discharge, particularly in the medical setting. However, there are no data regarding the benefit of this tool in cancer patients. Our aim was to evaluate the impact of a computer-alert system for VTE prevention in patients with cancer, particularly in those admitted to the Oncology/Haematology ward, comparing the results with the rest of inpatients at a university teaching hospital. The study included 32,167 adult patients hospitalised during the first semesters of years 2006 to 2010, 9,265 (28.8%) with an active malignancy. Appropriate prophylaxis in medical patients, significantly increased over time (from 40% in 2006 to 57% in 2010) and was maintained over 80% in surgical patients. However, while e-alerts were associated with a reduction of the incidence of VTE during hospitalisation in patients without cancer (odds ratio [OR] 0.31; 95% confidence interval [CI], 0.15-0.64), the impact was modest in cancer patients (OR 0.89; 95% CI, 0.42-1.86) and no benefit was observed in patients admitted to the Oncology/Haematology Departments (OR 1.11; 95% CI, 0.45-2.73). Interestingly, 60% of VTE episodes in cancer patients during recent years developed despite appropriate prophylaxis. Contrary to the impact on hospitalised patients without cancer, implementation of e-alerts for VTE risk did not prevent VTE effectively among those with malignancies.
    Thrombosis and Haemostasis 05/2013; 110(1). · 5.76 Impact Factor
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    ABSTRACT: Background. Type 1 diabetes is associated with vascular morbidity. The aim of this study was to evaluate the role of polymorphisms rs1410996 CFH and rs10490924 ARMS2 with proliferative diabetic retinopathy and coronary disease in type 1 diabetes patients. Material and methods. We present a retrospective study that analyses the clinical characteristics and the polymorphisms rs1410996 CFH and rs10490924 ARMS2 of 147 type 1 diabetes patients. Results. The patients who developed proliferative diabetic retinopathy in the first 20 years carried the rs1410996 CFH polymorphism. The overall risk-allele frequency was significantly higher among patients with coronary artery disease than in those without it (75 vs. 53%, p<0.001). Conclusions. rs1410996 CFH polymorphism could be associated with both proliferative diabetic retinopathy and coronary artery disease in type 1 diabetes patients. However, rs10490924 ARMS2 does not seem to be associated either with retinopathy or coronary artery disease.
    Anales del sistema sanitario de Navarra 12/2012; 35(3):425-432. · 0.35 Impact Factor
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    ABSTRACT: The leading cause of cardioembolic stroke is atrial fibrillation (AF), which predisposes to atrial thrombus formation. Although rheological alterations promote a hypercoagulable environment, as yet undefined factors contribute to thrombogenesis. The role of the endocardium has barely been explored. To approach this topic, rapid atrial pacing (RAP) was applied in four pigs to mimic AF. Left and right endocardial cells were isolated separately and their gene expression pattern was compared with that of four control pigs. The AF-characteristic rhythm disorders and endothelial nitric oxide synthase down-regulation were successfully reproduced, and validated RAP to mimic AF. A change was observed in the transcriptomic endocardial profile after RAP: the expression of 364 genes was significantly altered (p<0.01), 29 of them having passed the B>0 criteria. The left atrial endocardium [325 genes (7 genes, B>0)] was largely responsible for such alterations. Blood coagulation, blood vessel morphogenesis and inflammatory response are among the most significant altered functions, and help to explain the activation of coagulation observed after RAP: D-dimer, 0.49 (1.63) vs. 0.23 (0.24) mg/l [median (interquartile range)] in controls, p=0.02. Furthermore, three genes directly related to thrombotic processes were differentially expressed after RAP: FGL2 [fold change (FC)=0.85; p=0.007], APLP2 (FC=-0.47; p=0.005) and ADAMTS-18 (FC=-0.69; p=0.004). We demonstrate for the first time that AF induces a global expression change in the left atrial endocardium associated with an activation of blood coagulation. The nature of some of the altered functions and genes provides clues to identify new therapeutic targets.
    Thrombosis and Haemostasis 07/2012; 108(4):742-9. · 5.76 Impact Factor
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    R Montes, J Díez, J Hermida
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    ABSTRACT: The old axiom "one protein, one function" no longer holds true. Activated protein C (APC), the serine protease which plays a central role in anticoagulation, has gained attention due to its unsuspected (until a decade ago) ability to promote cell signaling mechanisms leading to cell/tissue protection. Since the PROWESS clinical trial initially pointed at APC as the only drug able to reduce the mortality associated with severe sepsis [1], many studies in animal models have demonstrated that APC shows promise in a variety of pathologies. Diabetic nephropathy, inflammatory bowel disease, systemic lupus erythematosus, amyotrophic lateral sclerosis (ALS), cancer metastasis and ischemic stroke are among the conditions that APC could help to fight against, thanks to its antiadhesive, antiapoptotic or barrier enhancement abilities [2]. © 2012 International Society on Thrombosis and Haemostasis.
    Journal of Thrombosis and Haemostasis 07/2012; 10(9):1733-5. · 6.08 Impact Factor
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    ABSTRACT: Efficient metastasis requires survival and adaptation of tumor cells to stringent conditions imposed by the extracellular milieu. Identification of critical survival signaling pathways in tumor cells might unveil novel targets relevant in disease progression. To investigate the contribution of activated protein C (APC) and its receptor (endothelial protein C receptor [EPCR]) in animal models of lung cancer metastasis and in patients with lung adenocarcinoma. Signaling pathway triggered by APC/EPCR and its relevance in apoptosis was studied in vitro. Functional significance was assessed by silencing and blocking antibodies in several in vivo models of lung cancer metastasis in athymic nude Foxn1(nu) mice. We examined EPCR levels using a microarray dataset of 107 patients. Immunohistochemical analysis was performed in an independent cohort of 295 patients with lung adenocarcinoma. The effects of APC binding to EPCR rapidly triggered Akt and extracellular signal-regulated kinase signaling pathways, leading to attenuated in vitro apoptosis. In vivo, silencing of EPCR expression or blocking APC/EPCR interaction reduced infiltration in the target organ, resulting in impaired prometastatic activity. Moreover, overexpression of EPCR induced an increased metastatic activity to target organs. Analysis of clinical samples showed a robust association between high EPCR levels and poor prognosis, particularly in stage I patients. EPCR and its ligand APC promote cell survival that contributes to tumor cell endurance to stress favoring prometastatic activity of lung adenocarcinoma. EPCR/APC is a novel target of relevance in the clinical outcome of early-stage lung cancer.
    American Journal of Respiratory and Critical Care Medicine 03/2012; 186(1):96-105. · 11.04 Impact Factor
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    ABSTRACT: In the last decade, the endothelial cell protein C/activated protein C receptor (EPCR) has received considerable attention. The role initially attributed to EPCR, i.e. the enhancement of protein C (PC) activation by the thrombin-thrombomodulin complex on the surface of the large vessels, although important, did not go beyond the haemostasis scenario. However, the discovery of the cytoprotective, anti-inflammatory and anti-apoptotic features of the activated PC (APC) and the required involvement of EPCR for APC to exert such actions did place the receptor in a privileged position in the crosstalk between coagulation and inflammation. The last five years have shown that PC/APC are not the only molecules able to interact with EPCR. Factor VII/VIIa (FVII/VIIa) and factor Xa (FXa), two other serine proteases that play a central role in haemostasis and are also involved in signalling processes influencing wound healing, tissue remodelling, inflammation or metastasis, have been reported to bind to EPCR. These observations have paved the way for an exploration of unsuspected new roles for the receptor. This review aims to offer a new image of EPCR in the light of its extended panel of ligands. A brief update of what is known about the APC-evoked EPCR-dependent cell signalling mechanisms is provided, but special care has been taken to assemble all the information available about the interaction of EPCR with FVII/VIIa and FXa.
    Thrombosis and Haemostasis 02/2012; 107(5):815-26. · 5.76 Impact Factor
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    ABSTRACT: The endothelial protein C receptor (EPCR) plays an important role in cardiovascular disease by binding protein C/activated protein C (APC). EPCR structure contains a hydrophobic groove filled with an unknown phospholipid needed to perform its function. It has not been established whether lipid exchange takes place in EPCR as a regulatory mechanism of its activity. Our objective was to identify this phospholipid and to explore the possibility of lipid exchange as a regulatory mechanism of EPCR activity driven by the endothelially expressed secretory group V phospholipase A(2) (sPLA(2)-V). We identified phosphatidylcholine (PCh) as the major phospholipid bound to human soluble EPCR (sEPCR). PCh in EPCR could be exchanged for lysophosphatidylcholine (lysoPCh) and platelet activating factor (PAF). Remarkably, lysoPCh and PAF impaired the protein C binding ability of sEPCR. Inhibition of sPLA(2)-V, responsible for lysoPCh and PAF generation, improved APC binding to endothelial cells. EPCR-dependent protein C activation and APC antiapoptotic effect were thus significantly enhanced. In contrast, endothelial cell supplementation with sPLA(2)-V inhibited both APC generation and its antiapoptotic effects. We conclude that APC generation and function can be modulated by changes in phospholipid occupancy of its endothelial cell receptor.
    Blood 12/2011; 119(12):2914-21. · 9.78 Impact Factor
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    ABSTRACT: High-sensitivity C-reactive protein (hs-CRP) is a marker for the risk of cardiovascular and overall mortality. However, information about the association between hs-CRP and mortality in patients with atrial fibrillation is scarce. A total of 293 participants of the Atherosclerosis Risk In Communities study with a history of AF and hs-CRP levels available were studied. During a median follow-up of 9.4 years, 134 participants died (46%). The hazard ratio of all-cause mortality associated with the highest versus the lowest tertile of hs-CRP was 2.52 (95% confidence interval 1.49 to 4.25) after adjusting for age, gender, history of cardiovascular diseases, and cardiovascular risk factors. A similar trend was observed for cardiovascular mortality (57 events; hazard ratio 1.90, 95% confidence interval 0.81 to 4.45). The Congestive heart failure, Hypertension, Age >75 years, Diabetes, and previous Stroke or transient ischemic attack (CHADS2) score was also associated with all-cause and cardiovascular mortality, with an adjusted hazard ratio of 3.39 (95% confidence interval 1.91 to 6.01) and 8.71 (95% confidence interval 2.98 to 25.47), respectively, comparing those with a CHADS2 score >2 versus a CHADS2 score of 0. Adding hs-CRP to a predictive model including the CHADS2 score was associated with an improvement of the C-statistic for total mortality (from 0.627 to 0.677) and for cardiovascular mortality (from 0.700 to 0.718). In conclusion, high levels of hs-CRP constitute an independent marker for the risk of mortality in patients with atrial fibrillation.
    The American journal of cardiology 09/2011; 109(1):95-9. · 3.58 Impact Factor
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    ABSTRACT: The protein C anticoagulant pathway plays a crucial role as a regulator of the blood clotting cascade. Protein C is activated on the vascular endothelial cell membrane by the thrombin-thrombomodulin complex. The endothelial protein C receptor binds protein C and further enhances protein C activation. Once formed, activated protein C down-regulates thrombin formation by inactivating factors Va and VIIIa and exerts cytoprotective effects through endothelial protein C receptor binding. An adequate generation of activated protein C depends on the precise assembly, on the surface of the endothelial cells, of thrombin, thrombomodulin, protein C, and endothelial protein C receptor. Therefore, any change in the efficiency of this assembly may cause a reduction or increase in activated protein C generation and modulate the risk of thrombosis. This review highlights the role of the endothelial protein C receptor in disease and discusses the association of its mutations with the risk of thrombosis.
    Thrombosis Research 09/2011; 128(5):410-6. · 3.13 Impact Factor
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    ABSTRACT: Atrial fibrillation is the most important risk factor for cardioembolic stroke. Thrombi form in the left atrial appendage rather than in the right. The causes of this different thrombogenicity are not well-understood. The goal herein was to compare the activation of the anticoagulant protein C and the thrombomodulin and endothelial protein C receptor/activated protein C receptor expression on the endocardium between right and left atria. We harvested the atria of 6 monkeys (Macaca fascicularis) and quantified their ability to activate protein C ex vivo and we measured the thrombomodulin and endothelial protein C receptor expression by immunofluorescence. We found the ability to activate protein C decreased by half (P=0.028) and there was lower expression of thrombomodulin in the left atrial endocardium than the right (52.5±19.9 and 72.1±18.8 arbitrary intensity units, mean±standard deviation; P=0.028). No differences were detected in endothelial protein C receptor expression. Impaired protein C activation on the left atrial endocardium attributable to low thrombomodulin expression may explain its higher thrombogenicity and play a role in cardioembolic stroke.
    Stroke 06/2011; 42(9):2622-4. · 6.16 Impact Factor
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    C Puy, J Hermida, R Montes
    Journal of Thrombosis and Haemostasis 06/2011; 9(6):1255-7. · 6.08 Impact Factor
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    ABSTRACT: Traces of activated factor VII (FVIIa) are required to maintain haemostasis. Activated factor X (FXa) is the main activator of FVII in the absence of tissue factor. However, little is known about how this mechanism is regulated. We and others reported the interaction between FVII and the endothelial cell protein C receptor (EPCR). We have analysed the role of EPCR in the FXa-dependent FVIIa generation. Activation was performed on the surface of human aortic endothelial cells in the presence or absence of a blocking anti-EPCR monoclonal antibody (mAb). Western-blot analyses revealed that FVII activation was increased twofold upon EPCR blocking. Kinetic analyses revealed that blocking doubled the catalytic efficiency for activation. Protein C was unable to mimic the effect of the anti-EPCR mAb on activation. Surface plasmon resonance experiments revealed that binding of EPCR and phospholipids to FVII were mutually exclusive. The 50% inhibitory concentration value for phospholipids to reduce the binding of FVIIa to EPCR was 57.67 +/- 0.11 micromol/l. Immunofluorescence experiments showed that EPCR and phosphatidylserine are located at different regions of the cell surface. We propose that EPCR downregulates FVII activation by moving it from phosphatidylserine-rich regions. In summary, this study described a new anticoagulant role for EPCR.
    British Journal of Haematology 04/2010; 149(1):111-7. · 4.94 Impact Factor
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    ABSTRACT: The endothelial protein C receptor (EPCR) plays an anticoagulant role by improving protein C activation. Although low levels of activated protein C (APC) constitute a thrombosis risk factor, the relationship between modulating EPCR function and thrombosis has not been addressed so far. Monoclonal antibodies (mAb) against murine EPCR were raised, and their ability to block protein C/APC binding was tested. The ferric chloride carotid artery injury model in mice was chosen to test the effect of anti-EPCR mAb on thrombus formation. The time to total occlusion of the vessel was analysed in three groups, given an isotype control mAb (IC), a blocking (RCR-16) or a non-blocking (RCR-20) anti-EPCR mAb. RCR-16 prevented the interaction between protein C/APC and EPCR as demonstrated by surface plasmon resonance and flow cytometry, and inhibited the activation of protein C on the endothelium. IC and RCR-20 were unable to induce such effects. In vivo , RCR-16 shortened the time to total vessel occlusion with respect to IC [13.4 +/- 1.0 (mean +/- SD) and 17.8 +/- 3.2 minutes, respectively, p<0.001]. Occlusive thrombi lasting for more than one hour were observed in all RCR-16-treated animals, but only in 43% of IC-treated ones. Results with RCR-20 were indistinguishable from those observed with IC. For the first time, a direct relationship between blocking EPCR and thrombosis is demonstrated. Blocking anti-EPCR autoantibodies can predispose to thrombosis episodes and may constitute a new therapeutic target.
    Thrombosis and Haemostasis 03/2010; 103(6):1239-44. · 5.76 Impact Factor
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    ABSTRACT: Abstract Background Different isoforms of VEGF-A (mainly VEGF121, VEGF165 and VEGF189) have been shown to display particular angiogenic properties in the generation of a functional tumor vasculature. Recently, a novel class of VEGF-A isoforms, designated as VEGFxxxb, generated through alternative splicing, have been described. Previous studies have suggested that these isoforms may inhibit angiogenesis. In the present work we have produced recombinant VEGF121/165b proteins in the yeast Pichia pastoris and constructed vectors to overexpress these isoforms and assess their angiogenic potential. Results Recombinant VEGF121/165b proteins generated either in yeasts or mammalian cells activated VEGFR2 and its downstream effector ERK1/2, although to a lesser extent than VEGF165. Furthermore, treatment of endothelial cells with VEGF121/165b increased cell proliferation compared to untreated cells, although such stimulation was lower than that induced by VEGF165. Moreover, in vivo angiogenesis assays confirmed angiogenesis stimulation by VEGF121/165b isoforms. A549 and PC-3 cells overexpressing VEGF121b or VEGF165b (or carrying the PCDNA3.1 empty vector, as control) and xenotransplanted into nude mice showed increased tumor volume and angiogenesis compared to controls. To assess whether the VEGFxxxb isoforms are differentially expressed in tumors compared to healthy tissues, immunohistochemical analysis was conducted on a breast cancer tissue microarray. A significant increase (p < 0.05) in both VEGFxxxb and total VEGF-A protein expression in infiltrating ductal carcinomas compared to normal breasts was observed. A positive significant correlation (r = 0.404, p = 0.033) between VEGFxxxb and total VEGF-A was found. Conclusions Our results demonstrate that VEGF121/165b are not anti-angiogenic, but weakly angiogenic isoforms of VEGF-A. In addition, VEGFxxxb isoforms are up-regulated in breast cancer in comparison with non malignant breast tissues. These results are to be taken into account when considering a possible use of VEGF121/165b-based therapies in patients.
    Molecular Cancer. 01/2010;
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    ABSTRACT: Different isoforms of VEGF-A (mainly VEGF₁₂₁, VEGF₁₆₅ and VEGF189) have been shown to display particular angiogenic properties in the generation of a functional tumor vasculature. Recently, a novel class of VEGF-A isoforms, designated as VEGF(xxx)b, generated through alternative splicing, have been described. Previous studies have suggested that these isoforms may inhibit angiogenesis. In the present work we have produced recombinant VEGF₁₂₁/₁₆₅b proteins in the yeast Pichia pastoris and constructed vectors to overexpress these isoforms and assess their angiogenic potential. Recombinant VEGF₁₂₁/₁₆₅b proteins generated either in yeasts or mammalian cells activated VEGFR2 and its downstream effector ERK1/2, although to a lesser extent than VEGF₁₆₅. Furthermore, treatment of endothelial cells with VEGF₁₂₁/₁₆₅b increased cell proliferation compared to untreated cells, although such stimulation was lower than that induced by VEGF₁₆₅. Moreover, in vivo angiogenesis assays confirmed angiogenesis stimulation by VEGF₁₂₁/₁₆₅b isoforms. A549 and PC-3 cells overexpressing VEGF₁₂₁b or VEGF₁₆₅b (or carrying the PCDNA3.1 empty vector, as control) and xenotransplanted into nude mice showed increased tumor volume and angiogenesis compared to controls. To assess whether the VEGF(xxx)b isoforms are differentially expressed in tumors compared to healthy tissues, immunohistochemical analysis was conducted on a breast cancer tissue microarray. A significant increase (p < 0.05) in both VEGF(xxx)b and total VEGF-A protein expression in infiltrating ductal carcinomas compared to normal breasts was observed. A positive significant correlation (r = 0.404, p = 0.033) between VEGF(xxx)b and total VEGF-A was found. Our results demonstrate that VEGF₁₂₁/₁₆₅b are not anti-angiogenic, but weakly angiogenic isoforms of VEGF-A. In addition, VEGF(xxx)b isoforms are up-regulated in breast cancer in comparison with non malignant breast tissues. These results are to be taken into account when considering a possible use of VEGF₁₂₁/₁₆₅b-based therapies in patients.
    Molecular Cancer 01/2010; 9:320. · 5.13 Impact Factor
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    ABSTRACT: Oxidative stress plays a critical role in the pathogenesis of hypertension. The NADPH oxidase constitutes a major source of superoxide anion in phagocytic cells, and its activation is associated with matrix metalloproteinase (MMP)-9 secretion by these cells. We investigated the effects of the angiotensin II type 1 receptor antagonist losartan and its metabolites (EXP3174 and EXP3179) on NADPH oxidase activity and MMP-9 secretion in human phagocytic cells. EXP3179, but not losartan and EXP3174, dose-dependently inhibited (P<0.05) phorbol myristate acetate and insulin-stimulated NADPH oxidase activity. EXP3179 also inhibited phorbol myristate acetate-induced NADPH oxidase in endothelial cells. In addition, EXP3179 inhibited (P<0.05) both phorbol myristate acetate-stimulated p47phox translocation from cytosol to membranes and protein kinase C activity. Affinity experiments and enzymatic assays confirmed that EXP3179 inhibited several protein kinase C isoforms. EXP3179 also inhibited (P<0.05) phorbol myristate acetate-stimulated MMP-9 secretion. In a study performed in 153 hypertensive patients, phagocytic NADPH oxidase activity was lower (P<0.05) in losartan-treated compared with untreated patients and in patients treated with other angiotensin II type 1 receptor antagonists or with angiotensin-converting enzyme inhibitors. Plasma levels of MMP-9 were lower (P<0.05) in losartan-treated hypertensives compared with the other group of patients. Thus, EXP3179 acts as a blocker of the NADPH oxidase in phagocytic cells by a potential mechanism that targets the protein kinase C signaling pathway. This effect can be involved in reduced MMP-9 secretion by these cells. It is proposed that the EXP3179 metabolite may confer to losartan the specific capacity to reduce oxidative stress mediated by phagocytic cells in hypertensive patients.
    Hypertension 08/2009; 54(4):744-50. · 6.87 Impact Factor

Publication Stats

520 Citations
239.75 Total Impact Points

Institutions

  • 1994–2012
    • Universidad de Navarra
      • • Ciencias cardiovasculares
      • • School of Medicine
      • • Department of Hematology
      Pamplona, Navarre, Spain
  • 2007
    • Leiden University Medical Centre
      • Department of Clinical Epidemiology
      Leiden, South Holland, Netherlands
  • 2002
    • Hospital Virgen del Camino
      Cádiz, Andalusia, Spain