Publications by authors named "Julia Carracedo"

57 Publications

A high magnesium concentration in citrate dialysate prevents oxidative stress and damage in human monocytes .

Clin Kidney J 2021 May 30;14(5):1403-1411. Epub 2020 Aug 30.

Dpto de Biología de Sistemas, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain.

Background: The use of dialysis fluids (DFs) during haemodialysis has been associated with increased oxidative stress and reduced serum magnesium (Mg) levels, contributing to chronic inflammation. Since the role of Mg in modulating immune function and reducing oxidative stress has been demonstrated, the aim of this study was to characterize whether increasing the Mg concentration in DFs could protect immune cells from oxidative stress and damage.

Methods: The effect of citrate [citrate dialysis fluid (CDF), 1 mM] or acetate [acetate dialysis fluid (ADF), 3 mM] dialysates with low (0.5 mM; routinely used) or high (1 mM, 1.25 mM and 2 mM) Mg concentrations was assessed in THP-1 human monocytes. The levels of reactive oxygen species (ROS), malondialdehyde (MDA) and oxidized/reduced (GSSG/GSH) glutathione were quantified under basal and inflammatory conditions (stimulation with lipopolysaccharide, LPS).

Results: The increase of Mg in CDF resulted in a significant reduction of ROS production under basal and inflammatory conditions (extremely marked in 2 mM Mg; P 0.001). These effects were not observed in ADF. Interestingly, in a dose-dependent manner, high Mg doses in CDF reduced oxidative stress in monocytes under both basal and inflammatory conditions. In fact, 2 mM Mg significantly decreased the levels of GSH, GSSG and MDA and the GSSG/GSH ratio in relation to 0.5 mM Mg.

Conclusions: CDF produces lower oxidative stress than ADF. The increase of Mg content in DFs, especially in CDF, could have a positive and protective effect in reducing oxidative stress and damage in immune cells, especially under inflammatory conditions.
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http://dx.doi.org/10.1093/ckj/sfaa131DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8087128PMC
May 2021

Microvesicles from indoxyl sulfate-treated endothelial cells induce vascular calcification .

Comput Struct Biotechnol J 2020 9;18:953-966. Epub 2020 Apr 9.

Departamento de Biología de Sistemas, Universidad de Alcalá (IRYCIS), Alcalá de Henares, Madrid, Spain.

Vascular calcification (VC), an unpredictable pathophysiological process and critical event in patients with cardiovascular diseases (CVDs), is the leading cause of morbi-mortality and disability in chronic kidney disease (CKD) patients worldwide. Currently, no diagnostic method is available for identifying patients at risk of VC development; the pathology is detected when the process is irreversible. Extracellular vesicles (EVs) from endothelial cells might promote VC. Therefore, their evaluation and characterization could be useful for designing new diagnostic tools. The aim of the present study is to investigate whether microvesicles (MVs) from endothelial cells damaged by uremic toxin and indoxyl sulfate (IS) could induce calcification in human vascular smooth muscle cells (VMSCs). Besides, we have also analyzed the molecular mechanisms by which these endothelial MVs can promote VC development. Endothelial damage has been evaluated according to the percentage of senescence in endothelial cells, differential microRNAs in endothelial cells, and the amount of MVs released per cell. To identify the role of MVs in VC, VSMCs were treated with MVs from IS-treated endothelial cells. Calcium, inflammatory gene expression, and procalcification mediator levels in VSMCs were determined. IS-treated endothelial cells underwent senescence and exhibited modulated microRNA expression and an increase in the release of MVs. VSMCs exposed to these MVs modulated the expression of pro-inflammatory genes and some mediators involved in calcification progression. MVs produced by IS-treated endothelial cells promoted calcification in VSMCs.
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http://dx.doi.org/10.1016/j.csbj.2020.04.006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7184105PMC
April 2020

Increasing the Magnesium Concentration in Various Dialysate Solutions Differentially Modulates Oxidative Stress in a Human Monocyte Cell Line.

Antioxidants (Basel) 2020 Apr 15;9(4). Epub 2020 Apr 15.

Departamento de Biología de Sistemas, Universidad de Alcalá, 28871 Alcalá de Henares, Madrid, Spain.

Oxidative stress is exacerbated in hemodialysis patients by several factors, including the uremic environment and the use of dialysis fluids (DFs) Since magnesium (Mg) plays a key role in modulating immune function and in reducing oxidative stress, we aimed to evaluate whether increasing the Mg concentration in different DFs could protect against oxidative stress in immunocompetent cells in vitro. Effect of ADF (acetate 3 mM), CDF (citrate 1 mM), and ACDF (citrate 0.8 mM + acetate 0.3 mM) dialysates with Mg at standard (0.5 mM) or higher (1, 1.25, and 2 mM) concentrations were assessed in THP-1 monocyte cultures. Reactive oxygen species (ROS) and malondialdehyde (MDA) levels were quantified under basal and uremic conditions (indoxyl sulfate (IS) treatment). Under uremic conditions, the three DFs with 0.5 mM Mg promoted higher ROS production and lipid damage than the control solution. However, CDF and ACDF induced lower levels of ROS and MDA, compared to that induced by ADF. High Mg concentration (1.25 and/or 2 mM) in CDF and ACDF protected against oxidative stress, indicated by reduced ROS and MDA levels compared to respective DFs with standard concentration of Mg. Increasing Mg concentrations in ADF promoted high ROS production and MDA content. Thus, an increase in Mg content in DFs has differential effects on the oxidative stress in IS-treated THP-1 cells depending on the dialysate used.
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http://dx.doi.org/10.3390/antiox9040319DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7222382PMC
April 2020

Mechanisms of Cardiovascular Disorders in Patients With Chronic Kidney Disease: A Process Related to Accelerated Senescence.

Front Cell Dev Biol 2020 20;8:185. Epub 2020 Mar 20.

Departamento Biología de Sistemas, Facultad de Medicina y Ciencias de la Salud (IRYCIS), Universidad de Alcalá, Alcalá de Henares, Madrid, Spain.

Cardiovascular diseases (CVDs), especially those involving a systemic inflammatory process such as atherosclerosis, remain the leading cause of morbidity and mortality in patients with chronic kidney disease (CKD). CKD is a systemic condition affecting approximately 10% of the general population. The prevalence of CKD has increased over the past decades because of the aging of the population worldwide. Indeed, CVDs in patients with CKD constitute a premature form of CVD observed in the general population. Multiple studies indicate that patients with renal disease undergo accelerated aging, which precipitates the appearance of pathologies, including CVDs, usually associated with advanced age. In this review, we discuss several aspects that characterize CKD-associated CVDs, such as etiopathogenic elements that CKD patients share with the general population, changes in the cellular balance of reactive oxygen species (ROS), and the associated process of cellular senescence. Uremia-associated aging is linked with numerous changes at the cellular and molecular level. These changes are similar to those observed in the normal process of physiologic aging. We also discuss new perspectives in the study of CKD-associated CVDs and epigenetic alterations in intercellular signaling, mediated by microRNAs and/or extracellular vesicles (EVs), which promote vascular damage and subsequent development of CVD. Understanding the processes and factors involved in accelerated senescence and other abnormal intercellular signaling will identify new therapeutic targets and lead to improved methods of diagnosis and monitoring for patients with CKD-associated CVDs.
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http://dx.doi.org/10.3389/fcell.2020.00185DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7099607PMC
March 2020

Hypoxia-Inducible Factor-1α: The Master Regulator of Endothelial Cell Senescence in Vascular Aging.

Cells 2020 01 13;9(1). Epub 2020 Jan 13.

Departamento Biología de Sistemas, Facultad de Medicina y Ciencias de la Salud (IRYCIS), Universidad de Alcalá, Alcalá de Henares, 28805 Madrid, Spain.

Aging is one of the hottest topics in biomedical research. Advances in research and medicine have helped to preserve human health, leading to an extension of life expectancy. However, the extension of life is an irreversible process that is accompanied by the development of aging-related conditions such as weakness, slower metabolism, and stiffness of vessels. It also debated that aging can be considered an actual disease with aging-derived comorbidities, including cancer or cardiovascular disease. Currently, cardiovascular disorders, including atherosclerosis, are considered as premature aging and represent the first causes of death in developed countries, accounting for 31% of annual deaths globally. Emerging evidence has identified hypoxia-inducible factor-1α as a critical transcription factor with an essential role in aging-related pathology, in particular, regulating cellular senescence associated with cardiovascular aging. In this review, we will focus on the regulation of senescence mediated by hypoxia-inducible factor-1α in age-related pathologies, with particular emphasis on the crosstalk between endothelial and vascular cells in age-associated atherosclerotic lesions. More specifically, we will focus on the characteristics and mechanisms by which cells within the vascular wall, including endothelial and vascular cells, achieve a senescent phenotype.
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http://dx.doi.org/10.3390/cells9010195DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7016968PMC
January 2020

MicroRNA-126 regulates Hypoxia-Inducible Factor-1α which inhibited migration, proliferation, and angiogenesis in replicative endothelial senescence.

Sci Rep 2019 05 14;9(1):7381. Epub 2019 May 14.

Departamento Biología de Sistemas, Facultad de Medicina y Ciencias de la Salud, Universidad de Alcalá (IRYCIS), Alcalá de Henares, Madrid, Spain.

Whereas a healthy endothelium maintains physiological vascular functions, endothelial damage contributes to the development of cardiovascular diseases. Endothelial senescence is the main determinant of endothelial dysfunction and thus of age-related cardiovascular disease. The objective of this study is to test the involvement of microRNA-126 and HIF-1α in a model of replicative endothelial senescence and the interrelationship between both molecules in this in vitro model. We demonstrated that senescent endothelial cells experience impaired tube formation and delayed wound healing. Senescent endothelial cells failed to express HIF-1α, and the microvesicles released by these cells failed to carry HIF-1α. Of note, HIF-1α protein levels were restored in HIF-1α stabilizer-treated senescent endothelial cells. Finally, we show that microRNA-126 was downregulated in senescent endothelial cells and microvesicles. With regard to the interplay between microRNA-126 and HIF-1α, transfection with a microRNA-126 inhibitor downregulated HIF-1α expression in early passage endothelial cells. Moreover, while HIF-1α inhibition reduced tube formation and wound healing closure, microRNA-126 levels remained unchanged. These data indicate that HIF-1α is a target of miRNA-126 in protective and reparative functions, and suggest that their therapeutic modulation could benefit age-related vascular disease.
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http://dx.doi.org/10.1038/s41598-019-43689-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6517399PMC
May 2019

Pancreatic autoantibodies and CD14+CD16+ monocytes subset are associated with the impairment of ß-cell function after simultaneous pancreas-kidney transplantation.

PLoS One 2019 22;14(2):e0212547. Epub 2019 Feb 22.

Maimonides Biomedical Research Institute of Cordoba (IMIBIC)/Reina Sofia University Hospital/University of Cordoba, Cordoba, Spain.

Pancreatic autoantibodies (AAb) has been associated with a worse pancreas graft survival after simultaneous pancreas-kidney transplantation (SPK). However, due to the variable time for AAb to become positive and the lack of early biomarkers suggesting such autoimmune activation, the mechanisms leading ß-cell destruction remain uncertain. The present study aimed to evaluate the association between post-transplant AAb and the functional impairment of the pancreatic ß-cell and also the association of such AAb with inflammation after SPK. In a longitudinal study, we analyzed the impact of post-transplant glutamic acid decarboxylase (GAD-65) and the insulinoma-associated autoantigen 2 (IA-2) AAb on pancreas graft function. Serum Hb1Ac and C-peptide (C-pep) were longitudinally compared between a group with positive posttransplant AAb (AAb+; n = 40) and another matched group with negative AAb (AAb-; n = 40) until the fifth year following seroconversion. In the cross-sectional analysis, we further evaluated the systemic signatures of inflammation by measuring pro-inflammatory CD14+CD16+ monocytes by flow-cytometry and interleukin 17-A serum levels in 38 SPK recipients and ten healthy controls. In the longitudinal study, patients with AAb+ showed higher levels of Hb1Ac (p<0.001) and lower C-pep levels (p<0.001) compared to those who remained AAb- throughout the follow-up. In the cross-sectional study, AAb+ patients showed a higher percentage of CD14+CD16+ monocytes compared with those with AAb- and the healthy controls (6.70±4.19% versus 4.0±1.84% and 3.44±0.93%; p = 0.026 and 0.009 respectively). Also, CD14+CD16+ monocytes correlated with Hb1Ac and C-pep serum levels. Multivariate logistic regression showed that posttransplant AAb+ was independently associated with a higher percentage of pro-inflammatory monocytes (adjusted-OR 1.59, 95%CI 1.05-2.40, p = 0.027). The group of patients with positive AAb also showed higher levels of IL17A as compared with the other groups (either healthy control or the negative AAb subjects). In conclusion, pancreatic AAb+ after SPK were not only associated with higher Hb1Ac and lower c-peptide serum levels but also with an increased percentage of CD14+CD16+ monocytes and higher levels of circulating IL17-A.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0212547PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6386378PMC
November 2019

Statins and antiplatelet agents are associated with changes in the circulatory markers of endothelial dysfunction in chronic kidney disease.

Nefrologia (Engl Ed) 2019 May - Jun;39(3):287-293. Epub 2019 Feb 4.

Servicio de Nefrología, Hospital Universitario Puerta de Hierro Majadahonda, Majadahonda, Madrid, España; REDInREN ISCiii 016/0091009 RETYC, Madrid, España.

Backgrounds And Purposes: Patients with chronic kidney disease (CKD) have higher risk of developing cardiovascular disease. In CKD patients the mechanisms involved in, endothelial damage and the role of different drugs used on these patients are not completely understood. The aim of this work is to analyze the effect of statins and platelet antiaggregant (PA) on endothelial microvesicles (EMVs) and other markers of endothelial dysfunction.

Experimental Approach: Cross-sectional study of 41 patients with CKD 3b-4 and 8 healthy volunteers. Circulating levels of EMVs, vascular endothelial growth factor (VEGF), and advance oxidized protein products (AOPPS) were quantified and the correlation with different comorbidity variables and therapeutic strategies were evaluated.

Results: EMVs are increased in CKD patients as compared with controls (171.1 vs. 68.3/μl, P<.001). It was observed a negative correlation between age and EMVs. Statins and PA were associated with a reduction in EMVs and VEGF levels, independently of the serum total cholesterol levels (TC). The levels of AOPPS and VEGF were not different in CKD vs. controls.

Conclusion: CKD is associated with a change in EMVs, VEGF and AOPP levels. The treatment with statins and PA normalizes these values to almost the observed in controls and this effect is independently of the prevailing TC level. These findings explain the existence of the pleiotropic effects of statins and PA which deserve further studies.
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http://dx.doi.org/10.1016/j.nefro.2018.11.001DOI Listing
May 2020

Endothelial Extracellular Vesicles Produced by Senescent Cells: Pathophysiological Role in the Cardiovascular Disease Associated with all Types of Diabetes Mellitus.

Curr Vasc Pharmacol 2019 ;17(5):447-454

Biology Systems Department, Physiology, Alcala University, Alcala de Henares, Madrid, Spain.

Endothelial senescence-associated with aging or induced prematurely in pathological situations, such as diabetes, is a first step in the development of Cardiovascular Disease (CVDs) and particularly inflammatory cardiovascular diseases. The main mechanism that links endothelial senescence and the progression of CVDs is the production of altered Extracellular Vesicles (EVs) by senescent endothelial cells among them, Microvesicles (MVs). MVs are recognized as intercellular signaling elements that play a key role in regulating tissue homeostasis. However, MVs produced by damage cell conveyed epigenetic signals, mainly involving microRNAs, which induce many of the injured responses in other vascular cells leading to the development of CVDs. Many studies strongly support that the quantification and characterization of the MVs released by senescent endothelial cells may be useful diagnostic tools in patients with CVDs, as well as a future therapeutic target for these diseases. In this review, we summarize the current knowledge linking senescence-associated MVs to the development of CVDs and discuss the roles of these MVs, in particular, in diabetic-associated increases the risk of CVDs.
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http://dx.doi.org/10.2174/1570161116666180820115726DOI Listing
May 2020

Senescent Microvesicles: A Novel Advance in Molecular Mechanisms of Atherosclerotic Calcification.

Int J Mol Sci 2018 Jul 9;19(7). Epub 2018 Jul 9.

Biology Systems Department, Physiology, Alcala University, Alcala de Henares, 28805 Madrid, Spain.

Atherosclerosis, a chronic inflammatory disease that causes the most heart attacks and strokes in humans, is the leading cause of death in the developing world; its principal clinical manifestation is coronary artery disease. The development of atherosclerosis is attributed to the aging process itself (biological aging) and is also associated with the development of chronic diseases (premature aging). Both aging processes produce an increase in risk factors such as oxidative stress, endothelial dysfunction and proinflammatory cytokines (oxi-inflamm-aging) that might generate endothelial senescence associated with damage in the vascular system. Cellular senescence increases microvesicle release as carriers of molecular information, which contributes to the development and calcification of atherosclerotic plaque, as a final step in advanced atherosclerotic plaque formation. Consequently, this review aims to summarize the information gleaned to date from studies investigating how the senescent extracellular vesicles, by delivering biological signalling, contribute to atherosclerotic calcification.
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http://dx.doi.org/10.3390/ijms19072003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6073566PMC
July 2018

Protein Carbamylation: A Marker Reflecting Increased Age-Related Cell Oxidation.

Int J Mol Sci 2018 May 17;19(5). Epub 2018 May 17.

Biology Systems Department, Physiology, Alcala University, Alcala de Henares, 28805 Madrid, Spain.

Carbamylation is a post-translational modification of proteins that may partake in the oxidative stress-associated cell damage, and its increment has been recently proposed as a "hallmark of aging". The molecular mechanisms associated with aging are related to an increased release of free radicals. We have studied whether carbamylated proteins from the peripheral blood of healthy subjects are related to oxidative damage and aging, taking into account the gender and the immune profile of the subjects. The study was performed in healthy human volunteers. The detection of protein carbamylation and malondialdehyde (MDA) levels was evaluated using commercial kits. The immune profile was calculated using parameters of immune cell function. The results show that the individuals from the elderly group (60⁻79 years old) have increased carbamylated protein and MDA levels. When considered by gender, only men between 60 and 79 years old showed significantly increased carbamylated proteins and MDA levels. When those subjects were classified by their immune profile, the carbamylated protein levels were higher in those with an older immune profile. In conclusion, the carbamylation of proteins in peripheral blood is related to age-associated oxidative damage and to an aging functional immunological signature. Our results suggest that carbamylated proteins may play an important role at the cellular level in the aging process.
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http://dx.doi.org/10.3390/ijms19051495DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5983744PMC
May 2018

Microvesicles Derived from Indoxyl Sulfate Treated Endothelial Cells Induce Endothelial Progenitor Cells Dysfunction.

Front Physiol 2017 8;8:666. Epub 2017 Sep 8.

Department of Animal Physiology II, Faculty of Biology, Complutense University of MadridMadrid, Spain.

Cardiovascular disease is a major cause of mortality in chronic kidney disease patients. Indoxyl sulfate (IS) is a typical protein-bound uremic toxin that cannot be effectively cleared by conventional dialysis. Increased IS is associated with the progression of chronic kidney disease and development of cardiovascular disease. After endothelial activation by IS, cells release endothelial microvesicles (EMV) that can induce endothelial dysfunction. We developed an model of endothelial damage mediated by IS to evaluate the functional effect of EMV on the endothelial repair process developed by endothelial progenitor cells (EPCs). EMV derived from IS-treated endothelial cells were isolated by ultracentrifugation and characterized for miRNAs content. The effects of EMV on healthy EPCs in culture were studied. We observed that IS activates endothelial cells and the generated microvesicles (IsEMV) can modulate the classic endothelial roles of progenitor cells as colony forming units and form new vessels . Moreover, 23 miRNAs were contained in IsEMV including four (miR-181a-5p, miR-4454, miR-150-5p, and hsa-let-7i-5p) that were upregulated in IsEMV compared with control endothelial microvesicles. Other authors have found that miR-181a-5p, miR-4454, and miR-150-5p are involved in promoting inflammation, apoptosis, and cellular senescence. Interestingly, we observed an increase in NFκB and p53, and a decrease in IκBα in EPCs treated with IsEMV. Our data suggest that IS is capable of inducing endothelial vesiculation with different membrane characteristics, miRNAs and other molecules, which makes maintaining of vascular homeostasis of EPCs not fully functional. These specific characteristics of EMV could be used as novel biomarkers for diagnosis and prognosis of vascular disease.
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http://dx.doi.org/10.3389/fphys.2017.00666DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5599774PMC
September 2017

Dietary magnesium supplementation prevents and reverses vascular and soft tissue calcifications in uremic rats.

Kidney Int 2017 11 29;92(5):1084-1099. Epub 2017 Jul 29.

Servicio de Nefrología (Red in Ren), GC13, Metabolismo del calcio, Calcificación Vascular, Instituto Maimónides de Investigación Biomédica de Córdoba/Hospital Universitario Reina Sofia/Universidad de Cordoba, Cordoba, Spain.

Although magnesium has been shown to prevent vascular calcification in vitro, controlled in vivo studies in uremic animal models are limited. To determine whether dietary magnesium supplementation protects against the development of vascular calcification, 5/6 nephrectomized Wistar rats were fed diets with different magnesium content increasing from 0.1 to 1.1%. In one study we analyzed bone specimens from rats fed 0.1%, 0.3%, and 0.6% magnesium diets, and in another study we evaluated the effect of intraperitoneal magnesium on vascular calcification in 5/6 nephrectomized rats. The effects of magnesium on established vascular calcification were also evaluated in uremic rats fed on diets with either normal (0.1%) or moderately increased magnesium (0.6%) content. The increase in dietary magnesium resulted in a marked reduction in vascular calcification, together with improved mineral metabolism and renal function. Moderately elevated dietary magnesium (0.3%), but not high dietary magnesium (0.6%), improved bone homeostasis as compared to basal dietary magnesium (0.1%). Results of our study also suggested that the protective effect of magnesium on vascular calcification was not limited to its action as an intestinal phosphate binder since magnesium administered intraperitoneally also decreased vascular calcification. Oral magnesium supplementation also reduced blood pressure in uremic rats, and in vitro medium magnesium decreased BMP-2 and p65-NF-κB in TNF-α-treated human umbilical vein endothelial cells. Finally, in uremic rats with established vascular calcification, increasing dietary magnesium from 0.1% magnesium to 0.6% reduced the mortality rate from 52% to 28%, which was associated with reduced vascular calcification. Thus, increasing dietary magnesium reduced both vascular calcification and mortality in uremic rats.
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http://dx.doi.org/10.1016/j.kint.2017.04.011DOI Listing
November 2017

Microvesicles from the plasma of elderly subjects and from senescent endothelial cells promote vascular calcification.

Aging (Albany NY) 2017 03;9(3):778-789

Departamento de Biología de Sistemas, Facultad de Medicina y Ciencias de la Salud, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain.

Vascular calcification is commonly seen in elderly people, though it can also appear in middle-aged subjects affected by premature vascular aging. The aim of this work is to test the involvement of microvesicles (MVs) produced by senescent endothelial cells (EC) and from plasma of elderly people in vascular calcification. The present work shows that MVs produced by senescent cultured ECs, plus those found in the plasma of elderly subjects, promote calcification in vascular smooth muscle cells. Only MVs from senescent ECs, and from elderly subjects' plasma, induced calcification. This ability correlated with these types of MVs' carriage of: a) increased quantities of annexins (which might act as nucleation sites for calcification), b) increased quantities of bone-morphogenic protein, and c) larger Ca contents. The MVs of senescent, cultured ECs, and those present in the plasma of elderly subjects, promote vascular calcification. The present results provide mechanistic insights into the observed increase in vascular calcification-related diseases in the elderly, and in younger patients with premature vascular aging, paving the way towards novel therapeutic strategies.
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http://dx.doi.org/10.18632/aging.101191DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5391231PMC
March 2017

Markers of endothelial damage in patients with chronic kidney disease on hemodialysis.

Am J Physiol Renal Physiol 2017 04 11;312(4):F673-F681. Epub 2017 Jan 11.

Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain;

Patients with Stage 5 chronic kidney disease who are on hemodialysis (HD) remain in a chronic inflammatory state, characterized by the accumulation of uremic toxins that induce endothelial damage and cardiovascular disease (CVD). Our aim was to examine microvesicles (MVs), monocyte subpopulations, and angiopoietins (Ang) to identify prognostic markers in HD patients with or without diabetes mellitus (DM). A total of 160 prevalent HD patients from 10 centers across Spain were obtained from the Biobank of the Nephrology Renal Network (Madrid, Spain): 80 patients with DM and 80 patients without DM who were matched for clinical and demographic criteria. MVs from plasma and several monocyte subpopulations (CD14/CD16, CD14/CD16) were analyzed by flow cytometry, and the plasma concentrations of Ang1 and Ang2 were quantified by ELISA. Data on CVD were gathered over the 5.5 yr after these samples were obtained. MV level, monocyte subpopulations (CD14/CD16 and CD14/CD16), and Ang2-to-Ang1 ratios increased in HD patients with DM compared with non-DM patients. Moreover, MV level above the median (264 MVs/µl) was associated independently with greater mortality. MVs, monocyte subpopulations, and Ang2-to-Ang1 ratio can be used as predictors for CVD. In addition, MV level has a potential predictive value in the prevention of CVD in HD patients. These parameters undergo more extensive changes in patients with DM.
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http://dx.doi.org/10.1152/ajprenal.00013.2016DOI Listing
April 2017

Hemodiafiltration With Endogenous Reinfusion Improved Microinflammation and Endothelial Damage Compared With Online-Hemodiafiltration: A Hypothesis Generating Study.

Artif Organs 2017 Jan 16;41(1):88-98. Epub 2016 May 16.

Nephrology Unit, Reina Sofía University Hospital, Córdoba.

Hemodiafiltration with endogenous reinfusion (HFR) after ultrafiltrate passage through a resin cartridge combines adsorption, convection, and diffusion. Our prospective single-center crossover study compared HFR and online-hemodiafiltration (OLHDF) effects on two uremic toxins and 13 inflammatory, endothelial status, or oxidative stress markers. After an 8-week run-in period of high-flux hemodialysis, 17 eligible stable dialysis patients (median age 65 years, 10 male) without overt clinical inflammation were scheduled for four 8-week periods in the sequence: HFR/OLHDF/HFR/OLHDF. Relative to OLHDF, HFR was associated with greater indoxyl sulfate removal and lesser abnormalities in all other study variables, namely circulating interleukin-6, tumor necrosis factor-alpha, proportions of activated proinflammatory (CD14+CD16+, CD14++CD16+) monocytes, endothelial progenitor cells, apoptotic endothelial microparticles, vascular endothelial growth factor, vascular cellular adhesion molecule, angiopoietins 2 and 1, annexin V, and superoxide dismutase. Differences were significant (P < 0.05) in median values of 13/15 variables. Study period comparisons were generally consistent with dialysis technique comparisons, as were data from the subgroup completing all study periods (n = 9). Our investigation provides hypothesis-generating results suggesting that compared with OLHDF, HFR improves protein-bound toxin removal, inflammatory and endothelial status, and oxidative stress.
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http://dx.doi.org/10.1111/aor.12704DOI Listing
January 2017

Aging-associated oxidized albumin promotes cellular senescence and endothelial damage.

Clin Interv Aging 2016 29;11:225-36. Epub 2016 Feb 29.

Department of Systems Biology, Physiology Unit, Universidad de Alcalá, Madrid, Spain.

Increased levels of oxidized proteins with aging have been considered a cardiovascular risk factor. However, it is unclear whether oxidized albumin, which is the most abundant serum protein, induces endothelial damage. The results of this study indicated that with aging processes, the levels of oxidized proteins as well as endothelial microparticles release increased, a novel marker of endothelial damage. Among these, oxidized albumin seems to play a principal role. Through in vitro studies, endothelial cells cultured with oxidized albumin exhibited an increment of endothelial damage markers such as adhesion molecules and apoptosis levels. In addition, albumin oxidation increased the amount of endothelial microparticles that were released. Moreover, endothelial cells with increased oxidative stress undergo senescence. In addition, endothelial cells cultured with oxidized albumin shown a reduction in endothelial cell migration measured by wound healing. As a result, we provide the first evidence that oxidized albumin induces endothelial injury which then contributes to the increase of cardiovascular disease in the elderly subjects.
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http://dx.doi.org/10.2147/CIA.S91453DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4780186PMC
September 2016

TNFα-Damaged-HUVECs Microparticles Modify Endothelial Progenitor Cell Functional Activity.

Front Physiol 2015 22;6:395. Epub 2015 Dec 22.

Departamento Biología de Sistemas, Facultad de Medicina y Ciencias de la Salud, Universidad de Alcalá Alcalá de Henares, Spain.

Endothelial progenitor cells (EPCs) have an important role in the maintenance of vascular integrity and homeostasis. While there are many studies that explain EPCs mechanisms action, there are few studies that demonstrate how they interact with other emerging physiological elements such as Endothelial Microparticles (EMPs). EMPs are membranous structures with a size between 100 and 1000 nm that act as molecular information transporter in biological systems and are known as an important elements in develop different pathologies; moreover a lot of works explains that are novel biomarkers. To elucidate these interactions, we proposed an in vitro model of endothelial damage mediated by TNFalpha, in which damaged EMPs and EPCs are in contact to assess EPCs functional effects. We have observed that damaged EMPs can modulate several EPCs classic factors as colony forming units (CFUs), contribution to repair a physically damaged endothelium (wound healing), binding to mature endothelium, and co-adjuvants to the formation of new vessels in vitro (angiogenesis). All of these in a dose-dependent manner. Damaged EMPs at a concentration of 10(3) MPs/ml have an activating effect of these capabilities, while at concentrations of 10(5) MPs/ml these effects are attenuated or reduced. This in vitro model helps explain that in diseases where there is an imbalance between these two elements (EPCs and damaged EMPs), the key cellular elements in the regeneration and maintenance of vascular homeostasis (EPCs) are not fully functional, and could explain, at least in part, endothelial dysfunction associated in various pathologies.
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http://dx.doi.org/10.3389/fphys.2015.00395DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4686689PMC
January 2016

LDL biochemical modifications: a link between atherosclerosis and aging.

Food Nutr Res 2015 3;59:29240. Epub 2015 Dec 3.

Departamento Biología de Sistemas, Facultad de Medicina y Ciencias de la Salud, Universidad de Alcalá, Madrid, Spain.

Atherosclerosis is an aging disease in which increasing age is a risk factor. Modified low-density lipoprotein (LDL) is a well-known risk marker for cardiovascular disease. High-plasma LDL concentrations and modifications, such as oxidation, glycosylation, carbamylation and glycoxidation, have been shown to be proatherogenic experimentally in vitro and in vivo. Atherosclerosis results from alterations to LDL in the arterial wall by reactive oxygen species (ROS). Evidence suggests that common risk factors for atherosclerosis raise the likelihood that free ROS are produced from endothelial cells and other cells. Furthermore, oxidative stress is an important factor in the induction of endothelial senescence. Thus, endothelial damage and cellular senescence are well-established markers for atherosclerosis. This review examines LDL modifications and discusses the mechanisms of the pathology of atherosclerosis due to aging, including endothelial damage and oxidative stress, and the link between aging and atherosclerosis.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4670441PMC
http://dx.doi.org/10.3402/fnr.v59.29240DOI Listing
December 2015

Changes in endothelial microparticles and endothelial progenitor cells in obese patients in response to surgical stress.

J Bone Joint Surg Am 2015 Mar;97(5):353-8

Nephrology Unit, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Reina Sofía University Hospital, Avenida Menéndez Pidal s/n, 14004, Córdoba, Spain. E-mail address for J. Carracedo:

Background: Obese patients undergoing surgery are at increased risk of intraoperative and postoperative cardiovascular complications. The present study was designed to study the changes in endothelial microparticles, endothelial progenitor cells, and adipokines in obese patients in response to limb ischemia during knee surgery.

Methods: This prospective study included seventy-four patients who underwent total knee arthroplasty. Patients were stratified in tertiles according to their body mass index. Flow cytometry was used for quantification and characterization of endothelial microparticles, endothelial progenitor cells, and adipokines. ELISA (enzyme-linked immunosorbent assay) was used to measure the adiponectin level.

Results: The number of endothelial microparticles was greater in obese compared with nonobese patients. The number of endothelial microparticles increased further immediately after surgery in all tertiles. Three days after surgery, endothelial microparticles returned to the basal preoperative level except in the most obese patients. The percentage of endothelial progenitor cells was lower in obese patients. Concentrations of adipokines increased after surgery, but the increase was more accentuated in obese patients.

Conclusions: Obese patients present with a high number of endothelial microparticles, a low number of endothelial progenitor cells, and high levels of adipokines, with further increases in adipokines after surgery, suggesting an inflammatory condition that worsens after surgery and may affect endothelial repair.
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http://dx.doi.org/10.2106/JBJS.N.00570DOI Listing
March 2015

Effect of uraemia on endothelial cell damage is mediated by the integrin linked kinase pathway.

J Physiol 2015 Feb 18;593(3):601-18; discussion 618. Epub 2014 Dec 18.

Department of Systems Biology, Universidad de Alcalá, Madrid, Spain; IRSIN, Spain; REDinREN (Instituto de Salud Carlos III), Madrid, Spain.

Key Points: Patients with chronic kidney disease have a higher risk of developing cardiovascular diseases than the general population. Their vascular endothelium is dysfunctional, among other things, because it is permanently exposed to uraemic toxins, several of which have poor clearance by conventional dialysis. Recent studies have demonstrated the important role of integrin-linked kinase (ILK) in the maintenance of endothelial integrity and in this study we investigate the involvement of ILK in the mechanism underlying vascular endothelial damage that occurs in uraemia. For the first time, we demonstrate the implication of ILK in the protection against endothelial cell damage (inhibition of proliferation, toxicity, oxidative stress and programed cell death) induced by uraemic serum from chronic kidney disease patients and uraemic toxins. This molecular mechanism may have clinical relevance because it highlights the importance of maintaining high levels of ILK activity to help preserve endothelial integrity, at least in early stages of chronic kidney disease.

Abstract: Patients with chronic kidney disease (CKD) have a higher risk of developing cardiovascular diseases. Their vascular endothelium is dysfunctional, among other things, because it is permanently exposed to uraemic toxins, several of which, mostly protein-bound compounds such as indoxyl sulfate (IS) and p-cresyl sulphate, having poor clearance by conventional dialysis, induce endothelial toxicity. However, the molecular mechanism by which uraemic toxins regulate early stages of endothelial dysfunction remains unclear. Recent studies have demonstrated the important role of integrin-linked kinase (ILK) in the maintenance of endothelial integrity. In this study, we investigate the involvement of ILK in the mechanism underlying vascular endothelial damage that occurs in uraemia. First, we show that incubation of EA.hy926 cells with human uraemic serum from CKD patients upregulates ILK activity. This ILK activation also occurs when the cells are exposed to IS (25-100 μg ml(-1)), p-cresol (10-100 μg ml(-1)) or both combined, compared to human serum control. Next, we observed that high doses of both toxins together induce a slight decrease in cell proliferation and increase apoptosis and reactive oxygen species production. Interestingly, these toxic effects displayed a strong increase when the ILK protein is knocked down by small interfering RNA, even at low doses of uraemic toxins. Abrogation of AKT has demonstrated the ILK/AKT signalling pathway involved in these processes. This study has demonstrated the implication of ILK in the protection against endothelial cell damage induced by uraemic toxins, a molecular mechanism that could play a protective role in the early stages of endothelial dysfunction observed in uraemic patients.
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http://dx.doi.org/10.1113/jphysiol.2014.283887DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4324708PMC
February 2015

Endothelial microparticles mediate inflammation-induced vascular calcification.

FASEB J 2015 Jan 23;29(1):173-81. Epub 2014 Oct 23.

Instituto Maimónides de Investigación Biomédica de Córdoba/Fundación de Investigaciones Biomédicas de Córdoba, Reina Sofía University Hospital, Córdoba, Spain; Redes Temáticas de Investigación Cooperativa en Salud Renal, Instituto de Salud Carlos III, Madrid, Spain.

Stimulation of endothelial cells (ECs) with TNF-α causes an increase in the expression of bone morphogenetic protein-2 (BMP-2) and the production of endothelial microparticles (EMPs). BMP-2 is known to produce osteogenic differentiation of vascular smooth muscle cells (VSMCs). It was found that EMPs from TNF-α-stimulated endothelial cells (HUVECs) contained a significant amount of BMP-2 and were able to enhance VSMC osteogenesis and calcification. Calcium content was greater in VSMCs exposed to EMPs from TNF-α-treated HUVECs than EMPs from nontreated HUVECs (3.56 ± 0.57 vs. 1.48 ± 0.56 µg/mg protein; P < 0.05). The increase in calcification was accompanied by up-regulation of Cbfa1 (osteogenic transcription factor) and down-regulation of SM22α (VSMC lineage marker). Inhibition of BMP-2 by small interfering RNA reduced the VSMC calcification induced by EMPs from TNF-α-treated HUVECs. Similar osteogenic capability was observed in EMPs from both patients with chronic kidney disease and senescent cells, which also presented a high level of BMP-2 expression. Labeling of EMPs with CellTracker shows that EMPs are phagocytized by VSMCs under all conditions (with or without high phosphate, control, and EMPs from TNF-α-treated HUVECs). Our data suggest that EC damage results in the release of EMPs with a high content of calcium and BMP-2 that are able to induce calcification and osteogenic differentiation of VSMCs.
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http://dx.doi.org/10.1096/fj.14-249706DOI Listing
January 2015

Endothelial damage and vascular calcification in patients with chronic kidney disease.

Am J Physiol Renal Physiol 2014 Dec 22;307(11):F1302-11. Epub 2014 Oct 22.

Instituto Maimónides de Investigación Biomédica de Córdoba, Reina Sofía University Hospital, University of Córdoba, Córdoba, Spain; Nephrology Unit, Reina Sofía University Hospital, Córdoba, Spain; RETICs Red Renal (Instituto de Salud Carlos III), Madrid, Spain; and

Vascular calcification (VC) is a frequent complication of chronic kidney disease (CKD) and is a predictor of cardiovascular morbidity and mortality. In the present study, we investigated the potential involvement of endothelial microparticles (MPs) and endothelial progenitor cells (EPCs) in the generation of VC in CKD patients. The number of circulating EMPs is greater in patients with VC than without VC (307 ± 167 vs. 99 ± 75 EMPs/μl, P < 0.001). The percentage of EPCs is significantly lower in patient with VC than in patients without VC (0.14 ± 0.11% vs. 0.25 ± 0.18%, P = 0.002). The number of EPCs expressing osteocalcin (OCN) was higher in VC patients (349 ± 63 cells/100,000) than in non-VC patients (139 ± 75 cells/100,000, P < 0.01). In vitro, MPs obtained from CKD patients were able to induce OCN expression in EPCs from healthy donors; the increase in OCN expression was more accentuated if MPs were obtained from CKD patients with VC. MPs from CKD patients also induced OCN expression in vascular smooth muscle cells and fibroblasts. In CKD patients, the rise in endothelial MPs associated with a decrease in the number of EPCs, suggesting an imbalance in the processes of endothelial damage and repair in CKD patients, mainly those with VC. Our results suggest that EPCs, through OCN expression, may directly participate in the process of VC.
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http://dx.doi.org/10.1152/ajprenal.00114.2014DOI Listing
December 2014

Klotho Prevents NFκB Translocation and Protects Endothelial Cell From Senescence Induced by Uremia.

J Gerontol A Biol Sci Med Sci 2015 Oct 22;70(10):1198-209. Epub 2014 Sep 22.

REDinREN, Servicio de Nefrología, Fundación para la Investigación Biomédica del Hospital Universitario La Paz, Instituto de Salud Carlos III, Fondos FEDER, Madrid, Spain. Physiology Department, Alcala de Henares University, Madrid, Spain.

In patients with renal disease, uremia raises oxidative stress and senescence in endothelial cells, which can lead to endothelial dysfunction and cardiovascular disease. Klotho protein is a β-glucuronidase capable of hydrolyzing steroid β-glucuronides. This protein is recognized as an antiaging gene, that modulate both stress-induced senescence and functional response. The aim of the study was to investigate how senescence and oxidative stress induced by uremia in endothelial cells affects Klotho expression and whether intra or extracellular Klotho has effects on the response of these cells. Senescence and oxidative stress was obtained by exposure to uremic serum. Telomere length, the enzyme β-galactosidase, and oxidative stress were studied by flow cytometry. Nuclear factor kappa B activity was determined by electrophoretic mobility shift assay. The expression of Klotho decreased with the uremia and preceded the manifestations of cell aging. Levels of intracellular Klotho decreases associated to endothelial senescence, and exogenous Klotho prevents cellular senescence by inhibiting the increase in oxidative stress induced by uremia and diminished the nuclear factor kappa B-DNA binding ability.
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http://dx.doi.org/10.1093/gerona/glu170DOI Listing
October 2015

Microparticles released by vascular endothelial cells increase hypoxia inducible factor expression in human proximal tubular HK-2 cells.

Int J Biochem Cell Biol 2014 Aug 28;53:334-42. Epub 2014 May 28.

Departamento de Biología de Sistemas, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain.

Microparticles are produced by vesiculation of the cell plasma membrane and serve as vectors of cell-to-cell communication. Co-culture experiments have shown that hypoxia-inducible factor-α (HIF-α)-regulated-genes are up-regulated in human renal proximal tubular HK-2 cells by endothelial cell factors which might be transported inside endothelial microparticles (EMP). Here we aimed to study in HK-2 cells the effect of EMP, produced by activated endothelial cells, on HIF-α and HIF-α-regulated vascular endothelial growth factor-A (VEGF-A). EMP, at a concentration much lower than that found in plasma, increased the expression of HIF-α/VEGF-A in a COX-2/EP2 receptor dependent manner. Since the EMP/cells ratio was ∼1/1000, we hypothesized that paracrine mediators produced by HK-2 cells amplified the initial signal. This hypothesis was confirmed by two facts which also suggested that the mediators were conveyed by particles released by HK-2 cells: (i) HIF-α was up-regulated in HK-2 cells treated with the pellet obtained from the conditioned medium of the EMP-treated HK-2 cells. (ii) In transwell experiments, EMP-treated cells increased the expression of HIF-α in untreated HK-2 cells. Interestingly, we detected these cells, particles that were released by EMP-treated HK-2 cells. Depending on the pathological context, activation of HIF-α and VEGF-A signaling in renal tissue/cells may have either beneficial or harmful effects. Therefore, our results suggest that their presence in the urinary space of EMP produced by activated endothelial cells may influence the outcome of a number of renal diseases.
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http://dx.doi.org/10.1016/j.biocel.2014.05.025DOI Listing
August 2014

Effectiveness of haemodiafiltration with ultrafiltrate regeneration in the reduction of light chains in multiple myeloma with renal failure.

Nefrologia 2013 Nov;33(6):788-96

Acute kidney failure in multiple myeloma (MM) occurs in 12%-20% of patients and is a poor prognostic factor for patient survival. Recent studies have shown that dialysis with a High-Cut-Off membrane (HCO) removes free light chains (FLC) effectively although with significant albumin loss. Other adsorption-based techniques, such as haemodiafiltration with ultrafiltrate regeneration by adsorption in resin (SUPRA-HFR), have not been studied. We present three cases of MM, all haemodialysis-dependent since diagnosis. Two cases were IgG kappa and one was IgA lambda. All patients were treated with chemotherapy and SUPRA-HFR. The aim of this study was to evaluate the effectiveness of SUPRA-HFR in the reduction of FLC and its effect on albumin. We collected blood samples pre- and post-dialysis, and ultrafiltrate (UF) samples pre- and post-resin 5 minutes into the session and 5 minutes from the end. The mean reduction rate of FLC in blood per session in the three patients was 53% and 63% (kappa) and 38% (lambda). In the UF, the mean FLC reduction rate was close to 99%, both at the start and at the end of dialysis, without the removal of albumin. With the results obtained we can conclude that this technique achieves an effective reduction of FLC, which is maintained throughout the session, without resin saturation and without albumin loss. Therefore, SUPRA-HFR is effective as an adjunctive therapy for MM.
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http://dx.doi.org/10.3265/Nefrologia.pre2013.Sep.12176DOI Listing
November 2013

Post-dilution high convective transport improves microinflammation and endothelial dysfunction independently of the technique.

Blood Purif 2013 8;35(4):270-8. Epub 2013 May 8.

Reina Sofia University Hospital, Nephrology Unit, Córdoba, Spain.

Background/aims: We examined the effects of different online hemodiafiltration techniques on microinflammation and endothelial damage/repair.

Methods: The study was designed as a prospective crossover study. Flow cytometry was used to measure CD14(+)CD16(+) monocytes, apoptotic endothelial microparticles (EMPs), and endothelial progenitor cells (EPCs).

Results: Patients treated with high-flux hemodialysis showed a marked chronic inflammatory state (HF-HD 11 ± 2) versus healthy subjects (HS 3.9 ± 2.3; p < 0.05). High convective transport, independent of the technique used, improves microinflammatory parameters (OL-HDF 7.3 ± 2.1 or MID 6.5 ± 3.4; p < 0.05) and the endothelial damage/repair balance compared to HF-HD (EPCs HF-HD 0.3 ± 0.2), with no differences found between the two modalities (EPCs OL-HDF 0.6 ± 0.1, MID 0.6 ± 0.2; p < 0.05).

Conclusion: An increase in convective transport improves the microinflammatory state and the endothelial damage/repair of these patients independently of the technique used.
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http://dx.doi.org/10.1159/000350611DOI Listing
March 2014

Cellular senescence determines endothelial cell damage induced by uremia.

Exp Gerontol 2013 Aug 25;48(8):766-73. Epub 2013 Apr 25.

Reina Sofía University Hospital, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Avda Menéndez Pidal s/n, 14004 Córdoba, Spain.

Renal dysfunction is closely associated with endothelial damage leading to cardiovascular disease. However, the extent to which endothelial damage induced by uremia is modulated by aging is poorly known. Aging can render endothelial cells more susceptible to apoptosis through an oxidative stress-dependent pathway. We examined whether senescence-associated to oxidative stress determines the injury induced by the uremia in endothelial cells. Human umbilical vein endothelial cells (HUVEC) was incubated with human uremic serum and, in the animal model, endothelial cells were obtained from aortas of uremic and no uremic rats. Vitamin C was used to prevent oxidative stress. Senescence, assessed by telomere length and enzyme-betagalactosidase (β-gal), reactive oxygen species (ROS), mitochondrial depolarization (JC-1 probe), caspase 3, and apoptosis were determined by flow cytometry. NF-κB activity was determined by Western blot. Uremic serum increased ROS and NF-κB in young and aging HUVEC. However only in aging cells, uremic serum induced apoptosis (vs young HUVEC, p<0.01). The endothelial damage induced by uremia seems to be related with the increased oxidative stress, since in both HUVEC and in the experimental model of renal disease in rats, vitamin C prevents endothelial apoptosis. However, vitamin C did not decrease the oxidative stress associated to senescence. These results showed that as compared with young cells, senescent cells have high sensitivity to damage associated to the oxidative stress induced by the uremia. Consequently, protecting senescent endothelial cells from increased oxidative stress might be an effective therapeutic approach in the treatment of vascular disorders in chronic kidney diseases.
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http://dx.doi.org/10.1016/j.exger.2013.04.004DOI Listing
August 2013

Klotho modulates the stress response in human senescent endothelial cells.

Mech Ageing Dev 2012 Nov-Dec;133(11-12):647-54. Epub 2012 Sep 21.

Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC)/Fundación de Investigaciones Biomédicas de Córdoba (FIBICO), Reina Sofía University Hospital, Córdoba, Spain.

Lack of Klotho expression in mice leads to premature aging and age-related diseases, including vascular diseases. The aim of this study was to determine how endothelial cell line senescence affects Klotho expression and whether intra- or extracellular Klotho has any effect on the response of senescent cells to oxidative stress. The study was performed using human endothelial cells (HUVEC); cell aging was obtained by prolongation of cell division to 42 population doublings (PD). Senescence was also obtained by exposure to TNFα, which causes cell changes resembling cellular senescence. The decline in Klotho preceded the manifestations of cell ageing: telomere shortening and β-galactosidase expression. Klotho was also reduced in cells exposed to the proinflammatory cytokine TNFα. The addition of exogenous Klotho to aging cells did not modify the proportion of cells with short telomeres or any other feature of cell aging; however, exogenous Klotho prevented the changes resembling premature cellular senescence associated with TNFα, such as the decrease in telomere length and the increase in β-galactosidase-positive cells. Likewise exogenous Klotho prevented the increases in reactive oxygen species (ROS) activity, mitochondrial potential and cell apoptosis induced by TNFα.
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http://dx.doi.org/10.1016/j.mad.2012.09.002DOI Listing
May 2013

Losartan prevents the development of the pro-inflammatory monocytes CD14+CD16+ in haemodialysis patients.

Nephrol Dial Transplant 2012 Jul 13;27(7):2907-12. Epub 2012 Jan 13.

Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC)/Fundación de Investigaciones Biomédicas de Córdoba (FIBICO), Córdoba, Spain.

Background: The principal cause of mortality in haemodialysis (HD) patients is cardiovascular disease, which is linked to chronic inflammation. Recent studies have demonstrated that angiotensin II receptor AT1 antagonists have anti-inflammatory properties. In this study, we evaluated the effect of losartan on CD14+CD16+ monocytes in HD patients. In addition, we developed an in vitro model to study the mechanisms by which losartan modulates these cells.

Methods: We divided 18 HD patients into two groups, based on anti-hypertensive treatment: 9 patients were treated with losartan (losartan group) and 9 received other anti-hypertensive drugs that did not affect the renin-angiotensin axis (no-losartan group). Losartan was withdrawn in five patients from the losartan group for 2 months. Ten healthy subjects were included as controls. Invitro, we studied the differentiation of monocytes from healthy donors on stimulation with interleukin (IL)-10, IL-4 and granulocyte monocytes colony-stimulating factor with or without losartan in the culture medium.

Results: In patients who were taking losartan, the percentage of monocytes that expressed CD14+CD16+ was lower compared with patients in the no-losartan group. The percentage of CD14+CD16+ was similar in the losartan group and healthy subjects. When losartan was withdrawn from five patients in the losartan group, the percentage of CD14+CD16+ monocytes increased compared with before withdrawal. In vitro, when we added losartan to the culture medium, CD14++CD16- monocytes failed to differentiate into CD14+CD16+ cells.

Conclusion: Losartan acts as an immunomodulator that prevents the development of CD14+CD16+ pro-inflammatory monocytes in HD patients.
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http://dx.doi.org/10.1093/ndt/gfr767DOI Listing
July 2012
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