Polycystin-1 Is a Crucial Regulator of BIN1 Expression and T-Tubule Remodeling Associated with the Development of Dilated Cardiomyopathy.

Cardiomyopathy is commonly observed in patients with autosomal dominant polycystic kidney disease (ADPKD), even when they have normal renal function and arterial pressure. The role of cardiomyocyte polycystin-1 (PC1) in cardiovascular pathophysiology remains unknown. PC1 is a potential regulator of BIN1 that maintains T-tubule structure, and alterations in BIN1 expression induce cardiac pathologies. We used a cardiomyocyte-specific PC1-silenced (PC1-KO) mouse model to explore the relevance of cardiomyocyte PC1 in the development of heart failure (HF), considering reduced BIN1 expression induced T-tubule remodeling as a potential mechanism. PC1-KO mice exhibited an impairment of cardiac function, as measured by echocardiography, but no signs of HF until 7-9 months of age. Of the PC1-KO mice, 43% died suddenly at 7 months of age, and 100% died after 9 months with dilated cardiomyopathy. Total BIN1 mRNA, protein levels, and its localization in plasma membrane-enriched fractions decreased in PC1-KO mice. Moreover, the BIN1 + 13 isoform decreased while the BIN1 + 13 + 17 isoform was overexpressed in mice without signs of HF. However, BIN1 + 13 + 17 overexpression was not observed in mice with HF. T-tubule remodeling and BIN1 score measured in plasma samples were associated with decreased PC1-BIN1 expression and HF development. Our results show that decreased PC1 expression in cardiomyocytes induces dilated cardiomyopathy associated with diminished BIN1 expression and T-tubule remodeling. In conclusion, positive modulation of BIN1 expression by PC1 suggests a novel pathway that may be relevant to understanding the pathophysiological mechanisms leading to cardiomyopathy in ADPKD patients.

Eficacia de una estrategia estandarizada y simplificada para tratamiento de la hipertensión arterial en Chile: la Iniciativa HEARTS en las Américas / Efficacy of a standardized and simplified strategy for the treatment of high blood pressure in Chile: the HEARTS Initiative in the Americas / Eficácia de uma estratégia padronizada e simplificada para o tratamento da hipertensão arterial no Chile: a iniciativa HEARTS nas Américas

RESUMEN Objetivo. Evaluar la eficacia de un protocolo estandarizado y simplificado basado en los pilares técnicos de la Iniciativa HEARTS para el control de pacientes hipertensos del Programa de Salud Cardiovascular en el primer nivel de atención de salud en Chile. Métodos. Estudio observacional longitudinal (cohorte histórica), en 2 centros de salud familiar del primer nivel de atención en Santiago, que comparó el control de presión arterial en adultos hipertensos logrado con el protocolo estandarizado y simplificado, frente al protocolo habitual, según las guías nacionales. Las innovaciones del protocolo estandarizado incluyeron cambios en la coordinación del equipo de salud, inicio de tratamiento farmacológico inmediatamente después de confirmación diagnóstica, tratamiento farmacológico estandarizado con combinación de al menos 2 o 3 fármacos antihipertensivos en un sólo comprimido, en una toma diaria. Se realizó seguimiento por 1 año para evaluar el porcentaje de adherencia al tratamiento y cumplimiento de metas de control de presión arterial (menor a 140/90 mmHg). Resultados. Se evaluaron 1 490 pacientes: 562 que utilizaron el protocolo estandarizado y simplificado y 928 tratados con el protocolo habitual (centros de salud familiar-1: 650, centros de salud familiar -2: 278). A 1 año de seguimiento, los pacientes del grupo del protocolo estandarizado y simplificado tuvieron mayor proporción de cumplimiento de metas de control de presión arterial (65% versus 37% y 41%, p<0,001) y mayor porcentaje de adherencia al tratamiento en comparación con aquellos con el protocolo habitual (71% versus 18% y 23%, p<0,001). Conclusiones. Los resultados muestran que el protocolo estandarizado y simplificado es más efectivo que el protocolo habitual en el control de hipertensión arterial en pacientes en tratamiento en el primer nivel de atención en Chile. Su implementación a nivel nacional podría contribuir a la disminución de eventos cardiovasculares mayores.

ABSTRACT Objective. To evaluate the effectiveness of a standardized and simplified protocol based on the technical pillars of the HEARTS Initiative for the control of hypertensive patients in the Cardiovascular Health Program at the first level of care in Chile. Methods. Longitudinal observational study (historical cohort) in two family health centers at the first level of care in Santiago. The control of blood pressure in hypertensive adults using a standardized and simplified protocol was compared to the usual protocol based on national guidelines. Innovations in the standardized protocol included changes in how the health team is coordinated, initiation of pharmacological treatment immediately after confirmed diagnosis, standardized pharmacological treatment with a combination of at least two or three antihypertensive drugs taken daily in a single tablet. Follow-up was conducted after one year to assess the percentage of adherence to treatment and achievement of blood pressure control targets (< 140/90 mmHg). Results. A total of 1490 patients were evaluated: 562 who followed the standardized and simplified protocol, and 928 who were treated with the usual protocol (family health centers: 650; family health centers: 278). After one year, patients in the standardized and simplified protocol group had a higher proportion of adherence to blood pressure control targets (65% versus 37% and 41%, p<0.001) and higher adherence to treatment compared to those following the usual protocol (71% versus 18% and 23%, p<0.001). Conclusions. The results show that the standardized and simplified protocol is more effective than the usual protocol in controlling arterial hypertension in patients undergoing treatment at the first level of care in Chile. Its implementation at the national level could contribute to a decrease in major cardiovascular events.

RESUMO Objetivo. Avaliar a eficácia de um protocolo padronizado e simplificado, com base nos pilares técnicos da iniciativa HEARTS, para o controle de pacientes com hipertensão arterial do Programa de Saúde Cardiovascular na atenção primária à saúde do Chile. Métodos. Estudo observacional longitudinal (coorte histórica) em 2 centros de atenção primária de saúde da família em Santiago, que comparou o controle da pressão arterial em adultos com hipertensão, atingido com o protocolo padronizado e simplificado, versus o protocolo habitual, de acordo com as diretrizes nacionais. As inovações do protocolo padronizado incluíram mudanças na coordenação da equipe de saúde, início do tratamento farmacológico imediatamente após a confirmação do diagnóstico e tratamento farmacológico padronizado com associação de pelo menos 2 ou 3 anti-hipertensivos em um único comprimido, tomados uma vez ao dia. O acompanhamento foi realizado por 1 ano para avaliar o percentual de adesão ao tratamento e o cumprimento das metas de controle da pressão arterial (menor que 140/90 mmHg). Resultados. Foram avaliados 1.490 pacientes: 562 que utilizaram o protocolo padronizado e simplificado e 928 que foram tratados com o protocolo habitual (unidade de saúde da família 1: 650, unidade de saúde da família 2: 278). Em 1 ano de seguimento, os pacientes do grupo do protocolo padronizado e simplificado apresentaram maior proporção de cumprimento das metas de controle da pressão arterial (65% versus 37% e 41%, p<0,001) e maior percentual de adesão ao tratamento, em comparação com aqueles que utilizaram o protocolo habitual (71% versus 18% e 23%, p<0,001). Conclusões. Os resultados mostram que o protocolo padronizado e simplificado é mais eficaz que o protocolo habitual no controle da hipertensão arterial em pacientes que estão em tratamento na atenção primária do Chile. Sua implementação no nível nacional poderia contribuir para a redução de eventos cardiovasculares maiores.

Glutathione S-Transferase and Clusterin, New Players in the Ischemic Preconditioning Renal Protection in a Murine Model of Ischemia and Reperfusion.

BACKGROUND/AIMS: Renal ischemia and reperfusion injury (IRI) involves oxidative stress, disruption of microvasculature due to endothelial cell damage, loss of epithelial cell polarity secondary to cytoskeletal alterations, inflammation, and the subsequent transition into a mesenchymal phenotype. Ischemic preconditioning (IPC) has been proposed as a therapeutic strategy to avoid/ameliorate the IRI. Since previous results showed that IPC could have differential effects in kidney cortex vs. kidney medulla, in the present study we analyzed the effectiveness and molecular mechanisms implicated in IPC in both kidney regions. METHODS: We evaluated 3 experimental groups of BALB/c male mice: control (sham surgery); renal ischemia (30 min) by bilateral occlusion of the renal pedicle and reperfusion (48 hours) (I/R); and renal IPC (two cycles of 5 min of ischemia and 5 min of reperfusion) applied just before I/R. Acute kidney injury was evaluated by glomerular filtration rate (GFR), Neutrophil Gelatinase-Associated Lipocalin (NGAL) blood level, and histologic analysis. Oxidative stress was studied measurement the Glutathione S-Transferase (GST) activity, GSH/GSSG ratio, and lipoperoxidation levels. Inflammatory mediators (IL-1ß, IL-6, Foxp3, and IL-10) were quantified by qRT-PCR. The endothelial (PECAM-1), epithelial (AQP-1), mesenchymal (Vimentin, Fascin, and Hsp47), iNOS, clusterin, and Hsp27 expression were evaluated (qRT-PCR and/or Western blot). RESULTS: The IPC protocol prevented the decrease of GFR, reduced the plasma NGAL, and ameliorated morphological damage in the kidney cortex after I/R. The IPC also prevented the downregulation of GST activity, lipoperoxidation and ameliorated the oxidized glutathione. In addition, IPC prevented the upregulation of vimentin, fascin, and Hsp47, which was associated with the prevention of the downregulation of AQP1 after I/R. The protective effect of IPC was associated with the upregulation of Hsp27, Foxp3, and IL-10 expression in the renal cortex. However, the upregulation of iNOS, IL-1ß, IL-6, and clusterin by I/R were not modified by IPC. CONCLUSION: IPC conferred better protection in the kidney cortex as compared to the kidney medulla. The protective effect of IPC was associated with amelioration of oxidative stress, tubular damage, and the induction of markers of Treg lymphocytes activity in the cortical region. Further studies are needed to evaluate if lower tubular cell stress/damage after I/R may explain the preferential induction of Treg response in the kidney cortex induced by IPC.

La inflamación en la hipertensión arterial, mecanismos de producción e implicancias terapéuticas / Role of inflammation in hypertension

Even though the mechanisms that mediate essential hypertension (HT) are not fully understood, an immunological-inflammatory mechanism could be the common pathway for diverse pathophysiological mechanisms. We analyze in a simplified way the participation of the immune system in HT. T lymphocytes (TL) and antigen presenting cells (APCs) are components of the immune system capable of generating proinflammatory cytokines. They cause endothelial damage, vasoconstriction, and decreased urinary sodium excretion. CD4+ and CD8+ TL are effector cells, causally implicated in the development of HT, whereas type γδ TL play their pathogenic role in HT enhancing endothelial dysfunction. Additionally, a immunomodulation decrease by regulatory TL, worsens endothelial dysfunction and reduces vasodilation in experimental HT. Results of recent studies indicate that lymphocyte activation would be mediated by antigens captured by antigen APCs for subsequent presentation to "naive" TL. On the other hand, proinflammatory states such as obesity, the change of the intestinal microbiota and the increase in salt intake favors TL and APC activation, contributing to HT development.

Sensibilidad aumentada a lidocaína: estudio genético de un caso / Increased sensitivity to lidocaine: Genetic study of a case

Systemic toxicity by local anesthetics (LAs) is a severe and feared complication in anesthetic practice that generally results from the administration of an inappropriately high dose of LAs or an injection at an inappropriate place, either intravascular or a site with high absorption[1]. However, it is known that the susceptibility to these drugs may vary within the population, which may occur due to genetic changes in the LA binding site, located in the potential-dependent Na+ channels (Nav), thus increasing or decreasing its affinity and, therefore, its clinical consequences. We present a case of a 61 years-old female patient with a medical history of increased sensitivity to LAs. In this scenario, a genetic study was performed to exclude a Nav channel dysfunction.

La toxicidad sistémica por anestésicos locales (ALs) es una grave y temida complicación en la práctica anestésica que generalmente resulta de la administración de una dosis inapropiadamente alta de ALs o a una inyección en un lugar inadecuado, llámese intravascular o un sitio al alta absorción[1]. A pesar de lo anterior, es conocido que la susceptibilidad al efecto de estos fármacos puede variar dentro de la población, lo cual puede ocurrir debido a cambios genéticos en el sitio de unión de los AL, localizado en los canales de Na+ dependientes de potencial (Nav), incrementando o disminuyendo así su afinidad y, por ende, sus consecuencias clínicas. Presentamos el caso de una paciente de 61 años con historia de sensibilidad aumentada a Als. En este escenario, se le ofreció un estudio genético para excluir una disfunción específica a nivel de canal Nav

Dendritic cells are crucial for cardiovascular remodeling and modulate neutrophil gelatinase-associated lipocalin expression upon mineralocorticoid receptor activation.

BACKGROUND: Adaptive immunity is crucial in cardiovascular and renal inflammation/fibrosis upon hyperactivation of mineralocorticoid receptor. We have previously demonstrated that dendritic cells can respond to mineralocorticoid receptor activation, and the neutrophil gelatinase-associated lipocalin (NGAL) in dendritic cells is highly increased during aldosterone (Aldo)/mineralocorticoid receptor-dependent cardiovascular damage. However, the interrelationship among dendritic cells, target organs inflammation/fibrosis induced by mineralocorticoid receptor, and NGAL-dependence remains unknown. OBJECTIVE: We studied the role of dendritic cells in mineralocorticoid receptor-dependent tissue remodeling and whether NGAL can modulate the inflammatory response of dendritic cells after mineralocorticoid receptor activation. METHODS: Cardiovascular and renal remodeling induced by Aldo and high-salt diet [nephrectomy-Aldo-salt (NAS) model] were analyzed in CD11c.DOG mice, a model which allows dendritic cells ablation by using diphtheria toxin. In addition, in-vitro studies in NGAL-knock out dendritic cells were performed to determine the immunomodulatory role of NGAL upon Aldo treatment. RESULTS: The ablation of dendritic cells prevented the development of cardiac hypertrophy, perivascular fibrosis, and the overexpression of NGAL, brain natriuretic peptide, and two profibrotic factors induced by NAS: collagen 1A1 and connective tissue growth factor. We determined that dendritic cells were not required to prevent renal hypertrophy/fibrosis induced by NAS. Between different immune cells analyzed, we observed that NGAL abundance was higher in antigen-presenting cells, while in-vitro studies showed that mineralocorticoid receptor stimulation in dendritic cells favored NGAL and IL-23 expression (p19 and p40 subunits), which are involved in the development of fibrosis and the Th17-driven response, respectively. CONCLUSION: NGAL produced by dendritic cells may play a pivotal role in the activation of adaptive immunity that leads to cardiovascular fibrosis during mineralocorticoids excess.

TRPM4 channel is involved in regulating epithelial to mesenchymal transition, migration, and invasion of prostate cancer cell lines.

Transient Receptor Potential Melastatin 4 (TRPM4) is a Ca2+ -activated and voltage-dependent monovalent cation channel, which depolarizes the plasma cell membrane, thereby modulating Ca2+ influx across Ca2+ -permeable pathways. TRPM4 is involved in different physiological processes such as T cell activation and the migration of endothelial and certain immune cells. Overexpression of this channel has been reported in various types of tumors including prostate cancer. In this study, a significant overexpression of TRPM4 was found only in samples from cancer with a Gleason score higher than 7, which are more likely to spread. To evaluate whether TRPM4 overexpression was related to the spreading capability of tumors, TRPM4 was knockdown by using shRNAs in PC3 prostate cancer cells and the effect on cellular migration and invasion was analyzed. PC3 cells with reduced levels of TRPM4 (shTRPM4) display a decrease of the migration/invasion capability. A reduction in the expression of Snail1, a canonical epithelial to mesenchymal transition (EMT) transcription factor, was also observed. Consistently, these cells showed a significant change in the expression of key EMT markers such as MMP9, E-cadherin/N-cadherin, and vimentin, indicating a partial reversion of the EMT process. Whereas, the overexpression of TRPM4 in LnCaP cells resulted in increased levels of Snail1, reduction in the expression of E-cadherin and increase in their migration potential. This study suggests a new and indirect mechanism of regulation of migration/invasion process by TRPM4 in prostate cancer cells, by inducing the expression of Snail1 gene and consequently, increasing the EMT.

l-NIL prevents the ischemia and reperfusion injury involving TLR-4, GST, clusterin, and NFAT-5 in mice.

On renal ischemia-reperfusion (I/R) injury, recruitment of neutrophils during the inflammatory process promotes local generation of oxygen and nitrogen reactive species, which, in turn, are likely to exacerbate tissue damage. The mechanism by which inducible nitric oxide synthase (iNOS) is involved in I/R has not been elucidated. In this work, the selective iNOS inhibitor l- N6-(1-iminoethyl)lysine (l-NIL) and the NOS substrate l-arginine were employed to understand the role of NOS activity on the expression of particular target genes and the oxidative stress elicited after a 30-min of bilateral renal ischemia, followed by 48-h reperfusion in Balb/c mice. The main findings of the present study were that pharmacological inhibition of iNOS with l-NIL during an I/R challenge of mice kidney decreased renal injury, prevented tissue loss of integrity, and improved renal function. Several novel findings regarding the molecular mechanism by which iNOS inhibition led to these protective effects are as follows: 1) a prevention of the I/R-related increase in expression of Toll-like receptor 4 (TLR-4), and its downstream target, IL-1ß; 2) reduced oxidative stress following the I/R challenge; noteworthy, this study shows the first evidence of glutathione S-transferase (GST) inactivation following kidney I/R, a phenomenon fully prevented by iNOS inhibition; 3) increased expression of clusterin, a survival autophagy component; and 4) increased expression of nuclear factor of activated T cells 5 (NFAT-5) and its target gene aquaporin-1. In conclusion, prevention of renal damage following I/R by the pharmacological inhibition of iNOS with l-NIL was associated with the inactivation of proinflammatory pathway triggered by TLR-4, oxidative stress, renoprotection (autophagy inactivation), and NFAT-5 signaling pathway.

Erythropoietin induces bone marrow and plasma fibroblast growth factor 23 during acute kidney injury.

It is accepted that osteoblasts/osteocytes are the major source for circulating fibroblast growth factor 23 (FGF23). However, erythropoietic cells of bone marrow also express FGF23. The modulation of FGF23 expression in bone marrow and potential contribution to circulating FGF23 has not been well studied. Moreover, recent studies show that plasma FGF23 may increase early during acute kidney injury (AKI). Erythropoietin, a kidney-derived hormone that targets erythropoietic cells, increases in AKI. Here we tested whether an acute increase of plasma erythropoietin induces FGF23 expression in erythropoietic cells of bone marrow thereby contributing to the increase of circulating FGF23 in AKI. We found that erythroid progenitor cells of bone marrow express FGF23. Erythropoietin increased FGF23 expression in vivo and in bone marrow cell cultures via the homodimeric erythropoietin receptor. In experimental AKI secondary to hemorrhagic shock or sepsis in rodents, there was a rapid increase of plasma erythropoietin, and an induction of bone marrow FGF23 expression together with a rapid increase of circulating FGF23. Blockade of the erythropoietin receptor fully prevented the induction of bone marrow FGF23 and partially suppressed the increase of circulating FGF23. Finally, there was an early increase of both circulating FGF23 and erythropoietin in a cohort of patients with severe sepsis who developed AKI within 48 hours of admission. Thus, increases in plasma erythropoietin and erythropoietin receptor activation are mechanisms implicated in the increase of plasma FGF23 in AKI.

Mineralocorticoids modulate the expression of the ß-3 subunit of the Na+, K+-ATPase in the renal collecting duct.

Renal sodium reabsorption depends on the activity of the Na+,K+-ATPase α/ß heterodimer. Four α (α1-4) and 3 ß (ß1-3) subunit isoforms have been described. It is accepted that renal tubule cells express α1/ß1 dimers. Aldosterone stimulates Na+,K+-ATPase activity and may modulate α1/ß1 expression. However, some studies suggest the presence of ß3 in the kidney. We hypothesized that the ß3 isoform of the Na+,K+-ATPase is expressed in tubular cells of the distal nephron, and modulated by mineralocorticoids. We found that ß3 is highly expressed in collecting duct of rodents, and that mineralocorticoids decreased the expression of ß3. Thus, we describe a novel molecular mechanism of sodium pump modulation that may contribute to the effects of mineralocorticoids on sodium reabsorption.

The Ski Protein is Involved in the Transformation Pathway of Aurora Kinase A.

Oncogenic kinase Aurora A (AURKA) has been found to be overexpresed in several tumors including colorectal, breast, and hematological cancers. Overexpression of AURKA induces centrosome amplification and aneuploidy and it is related with cancer progression and poor prognosis. Here we show that AURKA phosphorylates in vitro the transcripcional co-repressor Ski on aminoacids Ser326 and Ser383. Phosphorylations on these aminoacids decreased Ski protein half-life. Reduced levels of Ski resulted in centrosomes amplification and multipolar spindles formation, same as AURKA overexpressing cells. Importantly, overexpression of Ski wild type, but not S326D and S383D mutants inhibited centrosome amplification and cellular transformation induced by AURKA. Altogether, these results suggest that the Ski protein is a target in the transformation pathway mediated by the AURKA oncogene.

The Expression of RAC1 and Mineralocorticoid Pathway-Dependent Genes are Associated With Different Responses to Salt Intake.

BACKGROUND: Rac1 upregulation has been implicated in salt-sensitive hypertension as a modulator of mineralocorticoid receptor (MR) activity. Rac1 could affect the expression of oxidative stress markers, such as hemoxigenase-1 (HO-1) or nuclear factor-B (NF-κB), and the expression of neutrophil gelatinase-associated lipocalin (NGAL), a cytokine upregulated upon MR activation. AIM: We evaluated RAC1 expression in relation of high salt intake and association with MR, NGAL, HO-1, and NF-κB expression, mineralo- and glucocorticoids levels, and inflammatory parameters. SUBJECTS AND METHODS: We studied 147 adult subjects. A food survey identified the dietary sodium (Na) intake. RAC1 expression was considered high or low according to the value found in normotensive subjects with low salt intake. We determined the gene expression of RAC1, MR, NGAL, HO-1, NF-κB, and 18S, isolated from peripheral leukocytes. We measured aldosterone, cortisol, sodium, potassium excretion, metalloproteinase (MMP9 y MMP2), and C-reactive protein. RESULTS: We identified 126 subjects with high Na-intake, 18 subjects had high, and 108 low-RAC1 expression. The subjects with high-RAC1 expression showed a significant increase in MR (P = 0.0002), NGAL (P < 0.0001) HO-1 (P = 0.0004), and NF-κB (P < 0.0001) gene expression. We demonstrated an association between RAC1 expression and MR (R sp 0.64; P < 0.0001), NGAL (R sp 0.48; P < 0.0001), HO-1 (R sp 0.53; P < 0.0001), and NF-κB (R sp0.52; P < 0.0001). We did not identify any association between RAC1 and clinical or biochemical variables. CONCLUSIONS: RAC1 expression was associated with an increase in MR, NGAL, NF-κB, and HO-1 expression, suggesting that RAC1 could be a mediator of cardiovascular damage induced by sodium, and may also useful to identify subjects with different responses to salt intake.

El efecto anti-hipertensivo de angiotensina-(1-9) es mediado por aumento temprano de la diuresis y natriuresis / Cardiac arrest associated to intramural hematoma of the anterior descending coronary artery

Introducción: Angiotensina (Ang)-(1-9) posee propiedades anti-hipertensivas y efecto protector a nivel cardiovascular en ratas hipertensas. Sin embargo, se desconoce si estos efectos están asociados a un mecanismo de desbalance de sodio a nivel renal. Objetivo: Determinar si el efecto anti-hipertensivo de Ang-(1-9) está asociado a un mecanismo diurético-na-triurético. Método: Ratas macho Sprague Dawley (200 ± 10g) fueron aleatorizadas para recibir Ang II (400 ng/kgmin) vía bomba osmótica. Como control se utilizaron ratas con operación sham (n=18). Después de 2 semanas desde la instalación de bomba, las ratas Sham e hipertensas fueron randomizadas para recibir vehículo (n=10), Ang-(1-9) (602 ng/kg/min, n=17) o una co-administración de Ang-(1-9) y A779 (100 ng kg-1min-1, n=7 bloqueador del receptor MAS) por 2 semanas. Resultados: Se determinó la presión arterial sistólica (PAS), masa ventricular relativa (MVR), área y perímetro de los cardiomiocitos (AC y PC) y la fracción volumétrica de colágeno total (FVCT). Para evaluar la diuresis y natriuresis se utilizaron ratas normotensas que fueron randomizadas para recibir vehículo (n=8) o Ang-(1-9) (600 ngKg-1min-1, n=8) por 6 días. Se observó un incremento significativo(p<0.05) de PAS (33%), MVR (17%), AC (64%), PC (20%), FVCT (46%). La administración crónica de Ang-(1-9) disminuyó PAS (20%), MVR (13 %), AC (35%), PC (20%) y FVCT (20%). Estos efectos no fueron mediados por el receptor MAS. Al comparar las ratas normotensas tratadas con vehículo o Ang-(1-9), se observó un aumento significativo de la diuresis y natriuresis en los días 2 y 3 en los animales con infusión de Ang-(1-9). Conclusión: Ang-(1-9) reduce la hipertensión y el remodelamiento cardíaco en ratas hipertensas. En animales normotensos se demostró que el tratamiento con Ang-(1-9)-induce diuresis y natriuresis. Este es el primer reporte que señala que el efecto de Ang-(1-9) está asociado a una regulación del sodio a nivel renal.

Background: Angiotensin-(1-9) has anti-hypertensive properties and protective cardiovascular effect in hypertensive rats. However, it is unknown whether its effects are related to a kidney mechanism to balance sodium. Aim: To determine if the anti-hypertensive effect of Ang-(1-9) is associated to a diuretic-natriuretic mechanism. Method: Sprague Dawley male rats (200±10 grs) were randomized to receive Angiotensin II by osmotic pump (400 ng/kg/min). Sham operated rats were utilized as control (n=18). Two weeks after pump setting, Sham rats with hypertension were randomized to receive placebo (n=10), Ang-(1-9)(602 ng/kg/min, n=17) or Ang-(1-9) plus A779 (Ang-(1-7) Receptor Mas blocker, 100ng/kg-1min-1, n=7) co-administration for two weeks. Arterial systolic pressure (PAS), ventricular relative mass (MVR), cardiomyocytes area and perimeter (AC and PC) and total collagen volume fraction (FVCT) were measured. Normotensive rats were utilized to evaluate diuresis and natriuresis which were randomized to receive placebo (n=8) or Ang-(1-9) (600ng/kg-1/min-1, n=8) for six days. Results: It was observed a significant rise (p<0.05) of PAS (33%), MVR (17%), AC (64%), PC (26%), FVCT (46%) was observed. Chronic administration of Ang-(1-9) reduced PAS (20%), MVR (13%), AC (35%), PC (20%) and FCVT (20%). All those effects were not mediated by Mas receptor. A significant raise was observed of diuresis and natriuresis at the second and third day of treatment in rats receiving Ang-(1-9) in comparison with normotensive rats treated with placebo. Conclusion: Ang-(1-9) reduces hypertension and cardiac remodeling in hypertensive rats. Ang-(1-9) induces natriuresis and diuresis in normotensive rats. This is the first report showing that Ang-(1-9) is associated to sodium balance in the kidney.

Low 2-methoxyestradiol levels at the first trimester of pregnancy are associated with the development of pre-eclampsia.

OBJECTIVE: To determine whether maternal plasma levels of 2-methoxyestradiol (2-ME) are decreased early in pregnancies that subsequently develop pre-eclampsia (PE) and whether this difference could be attributed to the presence of Val158Met catechol-O-methyltransferase (COMT) polymorphism in the placenta. METHODS: Clinical characteristics and plasma samples were collected at 11 to 14 weeks prospectively in a cohort of patients. From them, 13 PE and 72 control pregnant women were chosen. Plasma soluble fms-like tyrosine kinase1 and placental growth factor levels were measured by electrochemiluminescence and 2-ME was measured by high-performance liquid chromatography with mass spectrometry/mass spectrometry detection. At delivery, placental tissue was collected and the Val158Met COMT polymorphism was determined by restriction fragment length polymorphism-PCR. RESULTS: At 11 to 14 weeks, patients who would develop PE have significantly lower plasma levels of 2-ME than controls [1.9 ± 2 standard error of the mean (SEM) vs 61.7 ± 27 pg/mL, P < 0.05]. The Val158Met polymorphism was more frequent in controls than in PE patients and the placental presence of COMT polymorphism was associated with a decreased risk of developing PE [PE: 23.1% vs control: 66.6%; χ(2) = 10.9, p = 0.0041]. CONCLUSIONS: Lower plasma concentrations of 2-ME during early pregnancy in patients who subsequently develop PE were found. Presence of placental Val158Met COMT polymorphism is associated with a decreased risk to develop PE, suggesting a protective role against PE.

Daño arterial asociado a la enfermedad renal crónica: evaluación mediante técnicas de laboratorio no invasivo en pacientes hemodializados / Assesment of arterial damage by noninvasive peripheral arterial tonometry in non-diabetic hemodialysis patients

Background: Hemodialysis patients (HD) display high rates of cardiac disease and mortality. The cardiovascular morbidity and mortality of HD patients is attributable in a significant proportion to endothelial dysfunction, arterial stiffness, and vascular calcifications. Aim: To measure vascular reactivity in HD subjects and compare them with healthy volunteers. Material and Methods: Forty eight non diabetic patients aged 58 ± 4.6 years (29 males) on hemodialysis for a mean lapse of 4.8 years were studied. Arterial stiffness was measured in the radial artery. Pulse wave velocity was measured by noninvasive peripheral arterial tonometry in carotid and femoral arteries. Endothelial function was assessed, measuring reactive hyperemia response after a 5 min period of ischemia. As a control, all values were also measured in age and gender-matched healthy volunteers. Results: Arterial stiffness was significantly higher in HD patients than controls (23.9 ± 3.3 and 18.4 ± 3.4% respectively, p < 0.05). HD subjects had an increased pulse wave velocity (10.0 ± 0.8 and 7.6 ± 0.9 m/s respectively, p < 0.05). A reduction in the change in pulse amplitude pressure, as a measure of arterial dysfunction, was only observed in male patients (1.7± 0.4 and2.7 ± 0.4 respectively p < 0.01). Conclusions: Noninvasive assessment of peripheral vascular function may be useful for the identification of patients at risk for late cardiac events.

IL-17A levels increase in the infarcted region of the left ventricle in a rat model of myocardial infarction

Th17 cells, a recently described subtype of CD4+ effector lymphocytes, have been linked to cell-mediated autoimmune and inflammatory diseases as well as to cardiovascular diseases. However, the participation of IL-17A in myocardial ischemic injury has not been clearly defined. We therefore conducted the present study to evaluate IL-17A and Th17-related cytokine levels in a rat model of myocardial infarction (MI). MI was induced in male Sprague Dawley rats by coronary artery ligation. Controls were sham-operated (Sh) or non-operated (C). Blood and samples from the left ventricle (LV) were collected at weeks 1 and 4 post-MI. At week 1, MI animals exhibited increased IL-6, IL-23 and TGF-β mRNA levels with no apparent change in IL-17 mRNA or protein levels in whole LV. Only TGF-β mRNA remained elevated at week 4 post-MI. However, further analysis revealed that IL-17A mRNA and protein levels as well as IL-6 and IL-23 mRNA were indeed increased in the infarcted region, though not in the remote non infarcted region of the LV, except for IL-23 mRNA. The increased expression of IL-17A and Th17-related cytokines in the infarcted region of LV, suggests that this proinflammatory pathway might play a role in early stages of post MI cardiac remodelling.

[Cardiovascular assessment of non diabetic patients on hemodialysis]. / Evolución del compromiso cardiovascular de pacientes insuficientes renales, en hemodiálisis, sin bloqueo del eje renina-angiotensina.

BACKGROUND: Diabetes mellitus is an important risk factor for cardiovascular complications among patients on hemodialysis. However, the incidence of these complications among non diabetic patients on hemodialysis is not well known. AIM: To assess the incidence of cardiovascular complications in non diabetic patients on hemodialysis. PATIENTS AND METHODS: Seventy five non diabetic patients aged 55.6 +/- 17 years (48 males), receiving hemodialysis three times a week were evaluated with laboratory tests, echocardiogram anda carotid ultrasound. In 26 patients, interleukin 6, tumor necrosis factor alpha, and intercellular adhesión molecule (ICAM-1) were also measured. Patients were followed during two years. RESULTS: The mean lapse of dialysis therapy was 6.5 +/-5 years. The main cause of renal failure was hypertension. Sixty two percent had systolic hypertension, 86% had concentric left ventricular hypertrophy, 43% had atrial dilatation and 60% had calcifications in the thoracic aorta. Compared with normal controls, patients had higher levels of interleukin 6, tumor necrosis factor alpha and ICAM-1. Carotid media thickness was also higher and increased in the two years of follow up. No correlations were found between ventricular hypertrophy and dialysis lapse, packed red cell volume, calcium phosphorus product, parathormone levels or median arterial pressure. No cardiovascular events were recorded during the follow up period. CONCLUSIONS: Non diabetic patients on chronic hemodialysis have a high frequency of ventricular hypertrophy, carotid media thickening, aortic calcifications and an increase in proinflammatory cytokines.

Regulation of the sodium-phosphate cotransporter Pit-1 and its role in vascular calcification.

Vascular calcification is caused by the deposition of basic calcium phosphate crystals in blood vessels, myocardium, and/or cardiac valves. Calcification decreases artery wall compliance, and arterial calcification is associated to mortality in hyperphosphatemic renal failure and diabetes mellitus. The calcification of the tunica media characterizes the arteriosclerosis observed with age, diabetes and end stage-renal disease, and it can develop independently from intima calcification. As part of the vascular calcification mechanism, vascular smooth muscle cells (VSMC) experience a transition from a contractile to an osteochondrogenic phenotype and a sequence of molecular events that are typical of endochondral ossification. The current evidence indicates a key role of increased phosphate uptake by VSMC for calcification, which supplies the substrate for hydroxyapatite formation and could trigger or potentiate VSMC transdiferentiation. The present review analyzes the sodium-phosphate cotransporter Pit-1, which is implicated in calcification. On the basis of the available data obtained in the study of vascular and osteoblastic experimental models, we discuss potential regulatory mechanisms that could lead to increased sodium-dependent phosphate uptake in vascular calcification.

Evolución del compromiso cardiovascular de pacientes insuficientes renales, en hemodiálisis, sin bloqueo del eje renina-angiotensina / Cardiovascular assessment of non diabetic patients on hemodialysis

Background: Diabetes mellitus is an important risk factor for cardiovascular complications among patients on hemodialysis. However, the incidence of these complications among non diabetic patients on hemodialysis is not well known. Aim: To assess the incidence of cardiovascular complications in non diabetic patients on hemodialysis. Patients and methods: Seventy five non diabetic patients aged 55.6 ± 17 years (48 males), receiving hemodialysis three times a week were evaluated with laboratory tests, echocardiogram anda carotid ultrasound. In 26 patients, interleukin 6, tumor necrosis factor alpha, and intercellular adhesión molecule (ICAM-1) were also measured. Patients were followed during two years. Results: The mean lapse of dialysis therapy was 6.5 ±5 years. The main cause of renal failure was hypertension. Sixty two percent had systolic hypertension, 86 percent had concentric left ventricular hypertrophy, 43 percent had atrial dilatation and 60 percent had calcifications in the thoracic aorta. Compared with normal controls, patients had higher levels of interleukin 6, tumor necrosis factor alpha and ICAM-1. Carotid media thickness was also higher and increased in the two years of follow up. No correlations were found between ventricular hypertrophy and dialysis lapse, packed red cell volume, calcium phosphorus product, parathormone levels or median arterial pressure. No cardiovascular events were recorded during the follow up period. Conclusions: Non diabetic patients on chronic hemodialysis have a high frequency of ventricular hypertrophy, carotid media thickening, aortic calcifications and an increase in proinflammatory cytokines.

Na+ -K+ -2Cl- cotransporter is implicated in gender differences in the response of the rat aorta to phenylephrine.

Inhibition of the Na(+)-K(+)-2Cl(-) cotransporter (NKCC1) with bumetanide reduced contractile responses to phenylephrine (PE) in male rat aortas (129+/-4% of 60 mM KCl-induced contraction control vs 108+/-7% bumetanide; PE 10(-5) M; P<0.01) but did not change equivalent responses in female rat aortas. Removal of the endothelium blunted the effect of NKCC1 inhibition on the response to PE (10(-5) M) in males, whereas in denuded aorta from female rats, bumetanide reduced this response (162+/-5% control vs 146+/-3% bumetanide; P<0.05). NKCC1 basal activity did not show gender differences in intact aortic rings, but in the presence of PE, bumetanide-sensitive (86)Rb(+)/K(+) uptake increased more in male than female aortas (179+/-8 in males vs 158+/-5 nmol (86)Rb(+)/K(+) min(-1) (g aorta)(-1) in females; P<0.05). PE did not stimulate NKCC1 activity in denuded aorta from male rats. However, in female rats, PE increased NKCC1 activity similarly in both denuded (169+/-11 nmol (86)Rb(+)/K(+) min(-1) (g aorta)(-1)) and intact aortas. Ovariectomy increased the bumetanide-sensitive (86)Rb(+)/K(+) uptake increase elicited by PE (223+/-17 nmol (86)Rb(+)/K(+) min(-1) (g aorta)(-1)) and hormone replacement with 17beta-estradiol prevented this effect (159+/-29 nmol (86)Rb(+)/K(+) min(-1) (g aorta)(-1)). Na(+),K(+)-ATPase basal activity, measured as ouabain-sensitive (86)Rb(+)/K(+) uptake, was similar in male and female rats, but the effect of PE was significantly less in intact male aortas (232+/-16 in males vs 296+/-25 nmol (86)Rb(+)/K(+) min(-1) (g aorta)(-1) in females; P<0.05). Our results suggest that PE induced activation of NKCC1 and Na(+),K(+)-ATPase in the rat aorta in a gender-dependent way.