Restriction of cytosolic Acetyl-CoA to promote healthy aging

Motivation: During the last century humans have reached the longest lifespan in History. However, the increase on lifespan is associated to the development of age-related diseases that limit the quality of life of aged individuals (1). Therefore, there is a current need to determine the molecular mechanisms underlining age-related pathologies and to develop novel effective therapies for these diseases. Acetyl-CoA (Ac-CoA) is a central metabolite in energy metabolism involved in protein acetylation, fatty acid synthesis and cholesterol synthesis (2,3), which may play a significant role modulating the intrinsic processes of aging. In this work, we studied the effects of 4 cytosolic Ac-CoA reducing agents; two inhibitors of the ATP citrate lyase; SB-204990 (SB) and hydroxycitric acid (HCA), an inhibitor of Ac-CoA synthase; allicin, and a inhibitor of the citrate isocitrate carrier; 1,2,3-benzenetricarboxylic acid (BTC).Methods: Mice were fed a Standard Diet (STD) or a High Fat Diet (HFD) supplemented with SB for 15 weeks. After in vivo studies, we performed WB on metabolic tissues. In liver tissue we performed a proteomic analysis by iTRAQ (Isobaric tags for relative and absolute quantification). In parallel, we have initiated a longevity assay using HCA. Necropsies have been performed to determine the cause of death. Finally, we are currently investigating the effects of BTC and allicin in murine physiology using three experimental approaches; a healthy STD, a prophylactic treatment using an obesogenic/diabetogenic HFD and a therapeutic treatment used in obese mice.Results: Preliminary in vivo results have shown improvements in metabolic health on mice treated with SB. Ex vivo analyses have indicated that SB modulates lipid metabolism. Proteomic analyses revealed a decrease in the expression of proinflammatory proteins in SB-treated and HFD-fed mice. HCA supplementation in healthy STD-fed mice has resulted in delayed early mortality in mice. Additionally, HCA treatment revealed potential benefits in muscle strength in wirehang test. Our research using BTC and allicin will generate results in the nearly future.Conclusions: Results of SB-treated and HFD-fed mice show a robust modulation in lipid metabolism and in inflammatory pathways, suggesting that the intervention could rescue the phenotype associated to a metabolic deregulation. The improvements observed in HCA-treated mice suggest that HCA could have geroprotective effects in early mortality

Loss of pancreas upon activated Wnt signaling is concomitant with emergence of gastrointestinal identity

Organ formation is achieved through the complex interplay between signaling pathways and transcriptional cascades. The canonical Wnt signaling pathway plays multiple roles during embryonic development including patterning, proliferation and differentiation in distinct tissues. Previous studies have established the importance of this pathway at multiple stages of pancreas formation as well as in postnatal organ function and homeostasis. In mice, gain-of-function experiments have demonstrated that activation of the canonical Wnt pathway results in pancreatic hypoplasia, a phenomenon whose underlying mechanisms remains to be elucidated. Here, we show that ectopic activation of epithelial canonical Wnt signaling causes aberrant induction of gastric and intestinal markers both in the pancreatic epithelium and mesenchyme, leading to the development of gut-like features. Furthermore, we provide evidence that β -catenin-induced impairment of pancreas formation depends on Hedgehog signaling. Together, our data emphasize the developmental plasticity of pancreatic progenitors and further underscore the key role of precise regulation of signaling pathways to maintain appropriate organ boundaries

Effect of Epas1 and Pcx inactivation in pancreatic β-cell formation and function.

According to the consensus model for GSIS (Glucose-Stimulated Insulin Secretion), glucose is rapidly metabolized and coupled to insulin secretion involving a substantial number of cofactors and metabolites intermediates such as ATP, NADPH and citrate, among many others (1). In particular, pyruvate carboxylase (PC) is a fundamental enzyme in redox cycling between NADH and NADPH and also participates in an intricate process known as “pyruvate cycling” which allows the anaplerotic entry of pyruvate in the krebs cycle (2).Pancreatic β-cells express abnormally high levels of pyruvate carboxylase (PC) and insignificant levels of phosphoenolpyruvate carboxylase, the enzyme necessary for gluconeogenesis. This implies that PC must play a different role in β-cells, such as insulin secretion, which is required for the "metabolic switch" from glycolytic to aerobic metabolism during β-cell maturation. It is also known that pyruvate carboxylase activity is elevated in mature β-cells but diminished under diabetic conditions. Recent studies have revealed that the Hypoxia Inducible factor (HIF) pathway plays an important role of in β-cell function (cita algun articulo nuestro). Both overexpression and inactivation of HIF-1α in β cells cause defects in insulin secretion. However, the role of HIF-2α in β-cell formation and function has been largely ignored despite been reported to be activated during diabetic conditions.In this project, we hypothesize that HIF-2α and pyruvate carboxylase activity during late pancreatic HIF-2α formation is critical for the metabolic switch that ocurrs in β-cell during early postnatal development and thus for proper β-cell function.In this study, we will analyze the expression of Epas1 (the gene encoding HIF-2α and Pcx) at different prenatal and postnatal stages by mRNA TaqMan essay. Using Cre/lox technology in mice, we will inactivate Epas1 and Pcx specifically in β-cells. Immunofluorescence and immunohistochemical assays will be carried out to determine specific markers of cell identity, vascularization, proliferation, and polarity in pancreatic tissue of Epas1- and Pcx-deficient mice. Finally, we will also evaluate the in vivo behavior of pancreatic β-cells in transgenic mice through glucose and insulin tolerance assays (GTT and ITT). This will help us understand the relationship between HIF-2 and PC activity and β-cell development and function, as well as whether HIF-2 and PC activity play a role in β-cell failure during diabetes

MEF2C regulates outflow tract alignment and transcriptional control of Tdgf1

Congenital heart defects are the most common birth defects in humans, and those that affect the proper alignment of the outflow tracts and septation of the ventricles are a highly significant cause of morbidity and mortality in infants. A late differentiating population of cardiac progenitors, referred to as the anterior second heart field (AHF), gives rise to the outflow tract and the majority of the right ventricle and provides an embryological context for understanding cardiac outflow tract alignment and membranous ventricular septal defects. However, the transcriptional pathways controlling AHF development and their roles in congenital heart defects remain incompletely elucidated. Here, we inactivated the gene encoding the transcription factor MEF2C in the AHF in mice. Loss of Mef2c function in the AHF results in a spectrum of outflow tract alignment defects ranging from overriding aorta to double-outlet right ventricle and dextro-transposition of the great arteries. We identify Tdgf1, which encodes a Nodal co-receptor (also known as Cripto), as a direct transcriptional target of MEF2C in the outflow tract via an AHFrestricted Tdgf1 enhancer. Importantly, both the MEF2C and TDGF1 genes are associated with congenital heart defects in humans. Thus, these studies establish a direct transcriptional pathway between the core cardiac transcription factor MEF2C and the human congenital heart disease gene TDGF1. Moreover, we found a range of outflow tract alignment defects resulting from a single genetic lesion, supporting the idea that AHF-derived outflow tract alignment defects may constitute an embryological spectrum rather than distinct anomalies

GATA4: a key factor for liver fibrosis regression

Motivation: Several studies have shown that the reversion of active HSCs to a quiescent state is required for liver fibrosis regression. Previous work in our lab have identified GATA4 as key factor for the maintenance of HSCs quiescence. Injection of adenovirus overexpressing GATA4 (Ad-GATA4) via the tail vein in CCl4-treated mice have been used as an approach to revert the fibrosis. Using this method, adenoviruses are sequestered by all hepatic cells. We will quantify the % of Adenoviruses that reach the HSCs and other liver cells to test whether the liver regression is due to the overexpression of GATA4 in active HSCs. A transcriptional repression of HIF2α has been uncover in the group as a molecular mechanism by which GATA4 inactivates fibrotic HSCs during liver fibrosis regression. Two conserved GATA sites in the Hif2α gene have been identified. We will test whether the repression of Hif2α by GATA4 requires these two GATA sites. Finally, we will develop a vector containing HSCs-specific enhancer from the Gata4 gene (hG2) fused to a luciferase reporter gene. Using this construct (hG2-luc), we will generate a stable cell line to screen FDA-approved drugs that activate Gata4 expression in active (fibrotic) HSCs to induce the quiescence. Methods: Adenovirus overexpressing GFP were injected in mice via the tail vein. Livers from treated mice were analyzed by immunofluorescence for GFP and Desmin (HSCs marker) or GFP and HNF1 (hepatocyte marker). Quantification of double marked cells will be done using ImageJ software. A region of Hif2α containing wild type or mutated GATA sites was fused to the luciferase reporter. 293T cells were transiently transfected with each reporter plasmids and pCI-GATA4 expression vector. Luciferase activity was measured using a commercial kit. Finally, we have cloned the HSCs-specific enhancer from the Gata4 gene into the pGL4-luciferase vector to generate stable LX2 cell line harboring this construct. Results: Around 50% of HSCs were positive for GFP and Desmin. Mutation of GATA sites in the Hif2α avoid transcriptional repression by GATA4. Finally, the pGL4-hG2-TK construction has been successfully generated to develop a stable cell line. Conclusions: Adenoviruses injection via tail vein in mice efficiently reach HSCs. GATA4 transcriptionally repress Hif2α via two identified conserved GATA sites. The hG2-luc construct to generate stable lines will allow us to identified potential drugs to induce liver fibrosis regression

The effect of maternal diabetes on the Wnt-PCP pathway during embryogenesis as reflected in the developing mouse eye

Embryopathies that develop as a consequence of maternal diabetes have been studied intensely in both experimental and clinical scenarios. Accordingly, hyperglycaemia has been shown to downregulate the expression of elements in the non-canonical Wnt-PCP pathway, such as the Dishevelled-associated activator of morphogenesis 1 (Daam1) and Vangl2. Daam1 is a formin that is essential for actin polymerization and for cytoskeletal reorganization, and it is expressed strongly in certain organs during mouse development, including the eye, neural tube and heart. Daam1gt/gt and Daam1gt/+ embryos develop ocular defects (anophthalmia or microphthalmia) that are similar to those detected as a result of hyperglycaemia. Indeed, studying the effects of maternal diabetes on the Wnt-PCP pathway demonstrated that there was strong association with the Daam1 genotype, whereby the embryopathy observed in Daam1gt/+ mutant embryos of diabetic dams was more severe. There was evidence that embryonic exposure to glucose in vitro diminishes the expression of genes in the Wnt-PCP pathway, leading to altered cytoskeletal organization, cell shape and cell polarity in the optic vesicle. Hence, the Wnt-PCP pathway appears to influence cell morphology and cell polarity, events that drive the cellular movements required for optic vesicle formation and that, in turn, are required to maintain the fate determination. Here, we demonstrate that the Wnt-PCP pathway is involved in the early stages of mouse eye development and that it is altered by diabetes, provoking the ocular phenotype observed in the affected embryos

Infiltrating CD16 +

Our aim was to characterize glomerular monocytes (Mo) infiltration and to correlate them with peripheral circulating Mo subsets and severity of lupus nephritis (LN). Methods. We evaluated 48 LN biopsy samples from a referral hospital. Recognition of Mo cells was done using microscopic view and immunohistochemistry stain with CD14 and CD16. Based on the number of cells, we classified LN samples as low degree of diffuse infiltration (<5 cells) and high degree of diffuse infiltration (≥5 cells). Immunophenotyping of peripheral Mo subsets was done using flow cytometry. Results. Mean age was 34.0±11.7 years and the mean SLEDAI was 17.5±6.9. The most common SLE manifestations were proteinuria (91%) and hypocomplementemia (75%). Severe LN was found in 70% of patients (Class III, 27%; Class IV, 43%). Severe LN patients and patients with higher grade of CD16+ infiltration had lower levels of nonclassical (CD14+CD16++) Mo in peripheral blood. Conclusions. Our results might suggest that those patients with more severe forms of LN had a higher grade of CD14+CD16+ infiltration and lower peripheral levels of nonclassical (CD14+CD16++) Mo and might reflect a recruitment process in renal tissues. However, given the small sample, our results must be interpreted carefully

Conoces tu color : Parte 3

La secretaría de Extensión de la Universidad Nacional de La Plata en el marco de la convocatoria de proyectos 2019, acreditó el proyecto multidisciplinario Conoces tu color 2, en el cual participan diferentes Unidades Académicas: Facultad de Odontología, Bellas Artes, Ciencias Exactas y Ciencias Naturales, dependientes de la Universidad Nacional de La Plata. Docentes y alumnos de dichas facultades intervinimos con distintas acciones en el proyecto, el cuál tuvimos que adaptar, teniendo en cuenta el contexto de pandemia, contemplando que el cambio de rutinas y comportamientos diarios afecta la salud de la población, consideramos como herramienta eficaz promover la educación para la salud, priorizando incorporar hábitos saludables en el cuidado bucodental; en momentos de pandemia cuidar la salud oral es una prioridad ya que una de las principales vías de entrada del SARS –COV2 es la vía oral. Las familias pertenecientes a los sectores más vulnerables de la sociedad presentan gran cantidad de lesiones bucodentales producidas por una dieta alta en hidratos de carbono, ausencia de higiene oral, inicio tardío del cepillado dental o escasa frecuencia del mismo.Facultad de Odontologí

Soy Niña

Este libro pretende contribuir al reencuentro de la educación con esas finalidades que verdaderamente importan a una niña o un niño: ser feliz, jugar, vivir juntos y (no) aprender. Para ello hemos puesto el arte, nuestras experiencias y el saber acumulado al servicio del disfrute, el cuestionamiento, el análisis crítico y la construcción común de un presente deseable. Un texto colaborativo coordinado por Ignacio Calderón Almendros y realizado por alumnado de Educación y Cambio Social en el Grado en Educación Infantil de la Universidad de Málaga

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