Phosphorylation of GATA4 at serine105 is required for left ventricular remodelling process in angiotensin II–induced hypertension in rats

Abstract In this study, we investigated whether local intramyocardial GATA4 overexpression affects the left ventricular (LV) remodelling process and the importance of phosphorylation at serine-105 (S105) for the actions of GATA4 in an angiotensin II (AngII)-induced hypertension rat model. Adenoviral constructs overexpressing wild type GATA4 or GATA4 mutated at S105 were delivered into the anterior LV free wall. AngII (33.3 µg x kg-1 x h-1) was administered via subcutaneously implanted minipumps. Cardiac function and structure were examined by echocardiography, followed by histological immunostainings of LV sections and gene expression measurements by RT-qPCR. The effects of GATA4 on cultured neonatal rat ventricular fibroblasts were evaluated. In AngII?induced hypertension, GATA4 overexpression repressed fibrotic gene expression, reversed the hypertrophic adult-to-foetal isoform switch of myofibrillar genes and prevented apoptosis, whereas histological fibrosis was not affected. Overexpression of GATA4 mutated at S105 resulted in LV chamber dilatation, cardiac dysfunction and had minor effects on expression of myocardial remodelling genes. Fibrotic gene expression in cardiac fibroblasts was differently affected by overexpression of wild type or mutated GATA4. Our results indicate that GATA4 reduces AngII-induced responses by interfering with pro-fibrotic and hypertrophic gene expressions. GATA4 actions on LV remodelling and fibroblasts are dependent on phosphorylation site S105.Peer reviewe

Transcription factor PEX1 modulates extracellular matrix turnover through regulation of MMP-9 expression

The phenylephrine-induced complex-1 (PEX1) transcription factor, also known as zinc-finger protein 260 (Zfp260), is an effector of endothelin-1 and alpha(1)-adrenergic signaling in cardiac hypertrophy. However, the role of PEX1 in transcriptional regulation of myocardial remodeling remains largely unknown. In the present study, we used PEX1 gain- and loss-of-function to examine the effects of PEX1 on left ventricular remodeling. Adenoviral constructs expressing PEX1, antisense PEX1, or LacZ were delivered by local injection into the anterior wall of the left ventricle in Sprague-Dawley rats. PEX1 overexpression led to induction of hypertrophic gene program and increased fibrosis. In agreement with this, the expression of genes involved in the fibrotic process, such as collagens I and III, matrix metalloproteinases (MMPs), fibronectin-1, transforming growth factor beta-1 and connective tissue growth factor, were significantly up-regulated following PEX1 overexpression, whereas silencing of PEX1 significantly inhibited the expression of pro-fibrotic genes and increased left ventricular ejection fraction and fractional shortening. In vitro luciferase reporter assays showed that PEX1 regulates the expression of MMP-9 by activating promoter. Furthermore, PEX1 gain- and loss-of-function experiments in rat neonatal cardiac fibroblasts and myocytes revealed that MMP-9 gene expression was affected by PEX1 predominantly in fibroblasts. Our results indicate that PEX1 is involved in regulating cardiac fibrosis and extracellular matrix turnover, particularly fibroblasts being responsible for the fibrosis-associated changes in gene expression. Furthermore, PEX1 activation of the MMP-9 promoter triggers the pro-fibrotic response directed by PEX1.Peer reviewe

Characterization of the Regulatory Mechanisms of Activating Transcription Factor 3 by Hypertrophic Stimuli in Rat Cardiomyocytes

Peer reviewe

Plasma Orexin-A Levels Do Not Undergo Circadian Rhythm in Young Healthy Male Subjects

Orexin-A (OXA) has been originally isolated from a precursor peptide prepro-orexin from the lateral hypothalamus. The orexin system has been attributed to important functions in sleep, arousal and regulation of energy homeostasis. In addition to its high levels in cerebrospinal fluid, OXA is present in blood. However, reported peptide concentrations in plasma vary significantly depending on the method used. Therefore, a specific and sensitive OXA radioimmunoassay (RIA) with solid phase extraction method was developed to determine whether plasma OXA concentrations is affected by acute feeding and/or wake and sleep in young healthy males. Blood samples were collected for 24 h from nine healthy males (aged 20–24 years; BMI 20.7–26.5) every 2 h starting at 11 a.m. Food was served at 12 p.m, 5:30 p.m, 8 p.m and 8 a.m and the sleep time was between 10 p.m and 7 a.m. Plasma samples were analyzed in addition for cortisol and melatonin levels. Blood pressure was monitored through the experimental period. OXA antibody was raised in rabbits. OXA antiserum had only minor cross-reactivity with prepro-orexin precursor (<0.001%), amino-terminal peptide (<0.001%), carboxy-terminal peptide (0.001%), and orexin-B (0.3%) with high sensitivity (0.15 pg/tube). Plasma OXA levels varied between 0.5 and 16 pg/ml in seven subjects and were undetectable (below 0.5 pg/ml) in two subjects. The OXA concentrations did not correlate to feeding nor wake/sleep, whereas cortisol, melatonin and mean arterial blood pressure presented a clear circadian rhythm in each subject. In conclusion, OXA is present in blood in low amounts and its levels do not follow autonomic nor neuroendocrine circadian rhythms. Thereby, studies examining regulatory mechanisms and influences of OXA from blood samples should interpret results very cautiously

Identificación de parásitos gastrointestinales en un criadero de avestruces (Struthio camelus) del departamento del Cauca

The ostriches have attractive productive characteristics for the market of meat and eggs, as well as by-products such as feathers, fats, and skin. In Colombia the production of this species is increasing and to maintain its population in captivity, preventive measures are being taken against viral, bacterial and parasitic diseases. The objective of this study is to identify gastrointestinal parasites in an ostrich hatchery in the Cauca state. Coprological material was collected from 38 animals, 19 Adults (> 7 years of age), 9 young (1 year), 10 chicks (1 month), this material was sent at 4 ° C to be processed and examined in the laboratory. Were identified cysts compatibles with Eimeria sp. (15,7%) and Balantidium sp. (13,2%) and eggs compatibles with Libyostrongylussp. (10,5%), there was no correlation between ages and parasitic load;also there was no correlation between sex and parasitic load. Although the animals sampled did not present clinical signs of parasitic disease, it is necessary to carry out further studies to understand the biological cycle of these parasites in ostrichs of this region, in the present study we suggested the presence of Libyostrongylus sp., which has been reported once in Colombia.Los avestruces poseen características productivas que la hacen una especie atractiva para el mercado de carne y huevos, además de otros subproductos como plumas, grasas,  y piel. En diferentes países del mundo, incluyendo a Colombia, la producción de esta especie está aumentando y para mantener su población en cautiverio se están tomando medidas preventivas contra enfermedades virales, bacterianas y parasitarias. El objetivo de este trabajo fueidentificar parásitos gastrointestinales en un criadero de avestruces del departamento del Cauca. Para el estudio, se colectó material coprológico de 38 animales, 19 adultos (> 7 años de edad), 9 Juveniles (1 año), 10 polluelos (1 mes), siendo enviado a 4 °C a un laboratorio donde fue procesado y examinado. Se identificaron quistes compatibles con Eimeria sp. (15,7%), Balantidium sp. (13,2%) y huevos compatibles con Libyostrongylus sp. (10,5%), no hubo correlación entre las edades y la carga parasitaria, así como, el sexo y la carga parasitaria. A pesar de que los animales muestreados no presentaron signos clínicos de enfermedad parasitaria, es necesario realizar más estudios para comprender ciclo biológico de estos parásitos en los avestruces de la región, en el presente trabajo se sugiere la presencia de Libyostrongylus sp., el cual ya ha sido reportado una vez en Colombia.&nbsp

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

4to. Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad. Memoria académica

Este volumen acoge la memoria académica de la Cuarta edición del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad, CITIS 2017, desarrollado entre el 29 de noviembre y el 1 de diciembre de 2017 y organizado por la Universidad Politécnica Salesiana (UPS) en su sede de Guayaquil. El Congreso ofreció un espacio para la presentación, difusión e intercambio de importantes investigaciones nacionales e internacionales ante la comunidad universitaria que se dio cita en el encuentro. El uso de herramientas tecnológicas para la gestión de los trabajos de investigación como la plataforma Open Conference Systems y la web de presentación del Congreso http://citis.blog.ups.edu.ec/, hicieron de CITIS 2017 un verdadero referente entre los congresos que se desarrollaron en el país. La preocupación de nuestra Universidad, de presentar espacios que ayuden a generar nuevos y mejores cambios en la dimensión humana y social de nuestro entorno, hace que se persiga en cada edición del evento la presentación de trabajos con calidad creciente en cuanto a su producción científica. Quienes estuvimos al frente de la organización, dejamos plasmado en estas memorias académicas el intenso y prolífico trabajo de los días de realización del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad al alcance de todos y todas

Identificación y clasificación de parásitos gastrointestinales en aves ornamentales adscritas al programa de monitoreo de fauna silvestre del centro de paso de la ciudad de San Juan de Pasto y riesgo sanitario en sus propietarios

En el presente estudio se ejecutaron dos muestreos seriados de materia fecal con un intervalo de 21 días, en 235 aves ornamentales y en sus propietarios. Las aves pertenecen a 13 especies distintas adscritas al programa de monitoreo de fauna silvestre del centro de paso de San Juan de Pasto. Para el análisis de las muestras de las aves se utilizaron dos métodos: Método del frotis directo de heces y Método de flotación con solución Salina Saturada. Los datos fueron analizados con el programa SPSS 13.0 para Windows, donde se realizó un análisis de chi-cuadrado. El 100% de las aves analizadas se encontraron parasitadas, a pesar de no haber manifestado sintomatología clínica dentro de los cuales se identificaron a: Giardia sp, Cryptosporidium sp, Isospora sp, Eimeria sp, Entamoeba sp, Histomona sp, Ascaridia sp, Capillaria sp, Heterakis sp y strongyloides sp. La prevalencia de Giardia sp, en las aves ornamentales fue bastante alta en comparación a los parásitos observados, siendo, canario, cacatúa y alondra las especies de aves más susceptibles. Giardia sp, Cryptosporidium sp. y Entamoeba sp, fueron los parásitos identificados en los propietarios que tuvieron relación con los parásitos de aves ornamentales, siendo este un hallazgo de importancia debido al posible riesgo zoonótico que representan estos protozoarios. Mediante la aplicación de una encuesta a los propietarios de las aves, se determinó que las medidas inadecuadas de higiene y desinfección, sumadas a la mala calidad del agua, pueden ser condiciones ideales para la multiplicación y propagación de parásitos gastrointestinales

Plasma orexin-A levels do not undergo circadian rhythm in young healthy male subjects

Abstract Orexin-A (OXA) has been originally isolated from a precursor peptide prepro-orexin from the lateral hypothalamus. The orexin system has been attributed to important functions in sleep, arousal and regulation of energy homeostasis. In addition to its high levels in cerebrospinal fluid, OXA is present in blood. However, reported peptide concentrations in plasma vary significantly depending on the method used. Therefore, a specific and sensitive OXA radioimmunoassay (RIA) with solid phase extraction method was developed to determine whether plasma OXA concentrations is affected by acute feeding and/or wake and sleep in young healthy males. Blood samples were collected for 24 h from nine healthy males (aged 20–24 years; BMI 20.7–26.5) every 2 h starting at 11 a.m. Food was served at 12 p.m, 5:30 p.m, 8 p.m and 8 a.m and the sleep time was between 10 p.m and 7 a.m. Plasma samples were analyzed in addition for cortisol and melatonin levels. Blood pressure was monitored through the experimental period. OXA antibody was raised in rabbits. OXA antiserum had only minor cross-reactivity with prepro-orexin precursor (<0.001%), amino-terminal peptide (<0.001%), carboxy-terminal peptide (0.001%), and orexin-B (0.3%) with high sensitivity (0.15 pg/tube). Plasma OXA levels varied between 0.5 and 16 pg/ml in seven subjects and were undetectable (below 0.5 pg/ml) in two subjects. The OXA concentrations did not correlate to feeding nor wake/sleep, whereas cortisol, melatonin and mean arterial blood pressure presented a clear circadian rhythm in each subject. In conclusion, OXA is present in blood in low amounts and its levels do not follow autonomic nor neuroendocrine circadian rhythms. Thereby, studies examining regulatory mechanisms and influences of OXA from blood samples should interpret results very cautiously

Hypertrophic stimuli induce ATF3 gene expression in cultured NRCM.

<p>Cardiomyocyte cell cultures were subjected to ET-1 (100 nM) stimulifor 1, 4, 12 and 24 hours (<b>A, B, D</b>), cyclic mechanical stretch for 1, 4, 12, 24 and 48 hours (<b>C, E</b>), or LPS (1 µg/ml) for 4 hours. ATF3 (<b>A, C, F</b>) and BNP (<b>D, E</b>) mRNA levels were normalized to 18S quantified from the same samples, and are presented relative to control cells. The results represent mean ± SEM (n = 8–18) from at least 3 independent experiments. <b>B,</b> ATF3 protein levels after ET-1 stimuli were determined by Western blotting and normalized to GAPDH loading control levels. Representative Western blots are shown, and bar graphs represent mean ± SEM (n = 7) from 3 independent experiments. *<i>P<</i>0.05; **<i>P<</i>0.01; ***<i>P<</i>0.001.</p