Phosphomannosylation and the functional analysis of the extended Candida albicans MNN4-like gene family

We thank Luz A. López-Ramírez (Universidad de Guanajuato) for technical assistance. This work was supported by Consejo Nacional de Ciencia y Tecnología (ref. CB2011/166860; PDCPN2014-247109, and FC 2015-02-834), Universidad de Guanajuato (ref. 000025/11; 0087/13; ref. 1025/2016; Convocatoria Institucional para Fortalecer la Excelencia Académica 2015; CIFOREA 89/2016), Programa de Mejoramiento de Profesorado (ref. UGTO-PTC-261), and Red Temática Glicociencia en Salud (CONACYT-México). NG acknowledges the Wellcome Trust (086827, 075470, 101873, and 200208) and MRC Centre for Medical Mycology for funding (N006364/1). KJ was supported by a research visitor grant to Aberdeen from China Scholarship Council (CSC No. 201406055024). The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fmicb.2017.02156/full#supplementary-materialPeer reviewedPublisher PD

XVI International Congress of Control Electronics and Telecommunications: "Techno-scientific considerations for a post-pandemic world intensive in knowledge, innovation and sustainable local development"

Este título, sugestivo por los impactos durante la situación de la Covid 19 en el mundo, y que en Colombia lastimosamente han sido muy críticos, permiten asumir la obligada superación de tensiones sociales, políticas, y económicas; pero sobre todo científicas y tecnológicas. Inicialmente, esto supone la existencia de una capacidad de la sociedad colombiana por recuperar su estado inicial después de que haya cesado la perturbación a la que fue sometida por la catastrófica pandemia, y superar ese anterior estado de cosas ya que se encontraban -y aún se encuentran- muchos problemas locales mal resueltos, medianamente resueltos, y muchos sin resolver: es decir, habrá que rediseñar y fortalecer una probada resiliencia social existente - producto del prolongado conflicto social colombiano superado parcialmente por un proceso de paz exitoso - desde la tecnociencia local; como lo indicaba Markus Brunnermeier - economista alemán y catedrático de economía de la Universidad de Princeton- en su libro The Resilient Society…La cuestión no es preveerlo todo sino poder reaccionar…aprender a recuperarse rápido.This title, suggestive of the impacts during the Covid 19 situation in the world, and which have unfortunately been very critical in Colombia, allows us to assume the obligatory overcoming of social, political, and economic tensions; but above all scientific and technological. Initially, this supposes the existence of a capacity of Colombian society to recover its initial state after the disturbance to which it was subjected by the catastrophic pandemic has ceased, and to overcome that previous state of affairs since it was found -and still is find - many local problems poorly resolved, moderately resolved, and many unresolved: that is, an existing social resilience test will have to be redesigned and strengthened - product of the prolonged Colombian social conflict partially overcome by a successful peace process - from local technoscience; As Markus Brunnermeier - German economist and professor of economics at Princeton University - indicates in his book The Resilient Society...The question is not to foresee everything but to be able to react...learn to recover quickly.Bogot

Role of Protein Mannosylation in the Candida tropicalis-Host Interaction

Mannans are components of the fungal wall attached to proteins via N- or O-linkages. In Candida albicans, Och1 is an α1,6-mannosyltransferase that adds the first mannose unit to the N-linked mannan outer chain; whereas Pmr1 is an ion pump that imports Mn2+ into the Golgi lumen. This cation is the cofactor of Golgi-resident mannosyltransferases, and thus Pmr1 is involved in the synthesis of both N- and O-linked mannans. Since we currently have limited information about the genetic network behind the Candida tropicalis protein mannosylation machinery, we disrupted OCH1 and PMR1 in this organism. The C. tropicalis pmr1Δ and och1Δ mutants showed increased doubling times, aberrant colony and cellular morphology, reduction in the wall mannan content, and increased susceptibility to wall perturbing agents. These changes were accompanied by increased exposure of both β1,3-glucan and chitin at the wall surface of both mutant strains. Our results showed that O-linked mannans are dispensable for cytokine production by human mononuclear cells, but N-linked mannans and β1,3-glucan are key ligands to trigger cytokine production in a co-stimulatory pathway involving dectin-1 and mannose receptor. Moreover, we found that the N-linked mannan core found on the surface of C. tropicalis och1Δ null mutant was capable of inducing cytokine production; and that a mannan-independent pathway for IL-10 production is present in the C. tropicalis-mononuclear cell interaction. Both mutant strains showed virulence attenuation in the Galleria mellonella and the mouse model of systemic candidiasis. Therefore, mannans are relevant for cell wall composition and organization, and for the C. tropicalis-host interaction. © Copyright © 2019 Hernández-Chávez, Clavijo-Giraldo, Novák, Lozoya-Pérez, Martínez-Álvarez, Salinas-Marín, Hernández, Martínez-Duncker, Gácser and Mora-Montes

The Sporothrix schenckii Gene Encoding for the Ribosomal Protein L6 Has Constitutive and Stable Expression and Works as an Endogenous Control in Gene Expression Analysis

Sporothrix schenckii is one of the causative agents of sporotrichosis, a worldwide-distributed mycosis that affects humans and other mammals. The interest in basic and clinical features of this organism has significantly increased in the last years, yet little progress in molecular aspects has been reported. Gene expression analysis is a set of powerful tools that helps to assess the cell response to changes in the extracellular environment, the genetic networks controlling metabolic pathways, and the adaptation to different growth conditions. Most of the quantitative methodologies used nowadays require data normalization, and this is achieved measuring the expression of endogenous control genes. Reference genes, whose expression is assumed to suffer minimal changes regardless the cell morphology, the stage of the cell cycle or the presence of harsh extracellular conditions are commonly used as controls in Northern blotting assays, microarrays, and semi-quantitative or quantitative RT-PCR. Since the biology of the organisms is usually species specific, it is difficult to find a reliable group of universal genes that can be used as controls for data normalization in experiments addressing the gene expression, regardless the taxonomic classification of the organism under study. Here, we compared the transcriptional stability of the genes encoding for elongation factor 1A, Tfc1, a protein involved in transcription initiation on Pol III promoters, ribosomal protein L6, histone H2A, β-actin, β-tubulin, glyceraldehyde 3-phosphate dehydrogenase, UAF30, the upstream activating factor 30, and the transcription initiation factor TFIID subunit 10, during the fungal growth in different culture media and cell morphologies. Our results indicated that only the gene encoding for the ribosomal protein L6 showed a stable and constant expression. Furthermore, it displayed not transcriptional changes when S. schenckii infected larvae of Galleria mellonella or interacted with immune cells. Therefore, this gene could be used as control for data normalization in expression assays. As a proof of concept, this gene was used to assess the expression of genes encoding for glycosidases involved in the protein N-linked glycosylation pathway, a histidine kinase whose expression is regulated during the fungal dimorphism, and a glycosidase that participates in sucrose assimilation

Influences of the Culturing Media in the Virulence and Cell Wall of Sporothrix schenckii, Sporothrix brasiliensis, and Sporothrix globosa

Sporothrix schenckii, Sporothrix brasiliensis, and Sporothrix globosa are etiological agents of sporotrichosis, a human subcutaneous mycosis. Although the protocols to evaluate Sporothrix virulence in animal models are well described, the cell preparation before inoculation is not standardized, and several culturing media are used to grow yeast-like cells. Here, we found that carbon or nitrogen limitation during fungal cell preparation negatively impacted the ability of S. schenckii and S. brasiliensis to kill Galleria mellonella larvae, but not S. globosa. The fungal growth conditions associated with the short median survival of animals were accompanied by increased hemocyte countings, phenoloxidase activity, and cytotoxicity. The fungal growth under carbon or nitrogen limitation also affected the cell wall composition of both S. schenckii and S. brasiliensis and showed increased exposure of β-1,3-glucan at the cell surface, while those growing conditions had a minimal impact on the S.globosa wall, which had higher levels of this polysaccharide exposed on the wall regardless of the culture condition. This polysaccharide exposure was linked to the increased ability of insect hemocytes to uptake fungal cells, suggesting that this is one of the mechanisms behind the lower virulence of S.globosa or cells from the other species grown in carbon or nitrogen limitation

Carta de Psicología No. 56

Entre los mecanismos de divulgación de la investigación de la Facultad de Psicología se cuenta con la publicación semestral de Carta de Psicología, espacio en el cual se publican artículos cortos resultado de investigaciones desarrolladas en los diferentes escenarios de formación, para visibilizar los productos derivados de los semilleros innovo, de investigación o grupos de estudio; al igual que aquellos derivados de la interacción académica con instituciones de orden nacional e internacional, los derivados de ejercicios de investigación en el aula de clase y de actividades de extensión. Esta publicación parte de un doble reconocimiento: en su comienzo, los artículos científicos fueron epístolas de las comunidades científicas, grupos cercanos de interlocución franca y abierta. En su avance, Carta de Psicología propende por la reflexión y el diálogo a partir del reconocimiento de las experiencias valiosas que construyen universidad y diversidad en la formación, los ejercicios de investigación del aula, los avances de los proyectos de semilleros de investigación, los avances de maestría y doctorado, las voces de los egresados, entre otros, de tal manera que sirva como referencia de lo que hacemos y de lo que somos. Esta filosofía orienta el último desarrollo de la política editorial de Carta de Psicología en cuatro secciones: Investigación formativa, Interacción académica, Investigación de aula y Extensión.Investigación, integración curricular y divulgación como ejes para el cumplimiento de las funciones sustantivas en la Facultad de Psicología. El cambio de la comunicación en las relaciones afectivosexuales debido al uso de las redes sociales. Consumo de sustancias psicoactivas: una problemática juvenil. Flexibilidad cognitiva en el deterioro cognitivo leve. Relación entre clima organizacional y engagement en empleados de Bogotá. Relación entre el estrés y el desempeño laboral: revisión teórica. Percepción del liderazgo transformacional con relación a las variables sociodemográficas de la población colombiana. Programas de Outplacement para trabajadores en relación con su calidad de vida. Violencia sexual y redes sociales. Los juegos en redes y la violencia autoinfligida. El sentido de comunidad y la crisis económica, social y política en Colombia. Consumo de alcohol de estudiantes universitarios antes y durante la pandemia COVID-19. Resultados preliminares. Uso de la tecnología para la aplicación del instrumento para valorar la comprensión de síntesis. Consecuencias de los modelos de pautas de crianza en el desarrollo infantil. La justicia más allá de la equidad: un breve comentario del libro Las fronteras de la justicia, de Martha Nussbaum. Conceptualización y consecuencias del maltrato Infantil Exploración de factores de riesgo y los efectosdel reclutamiento forzado en el desarrollo infantil. Indicadores de aprendizaje para la educación integral de la sexualidad. Instrumento de medición de afectividad y erotismo en trabajadoras sexuales de Bogotá. Toma de decisiones y vida sexual: autocuidado, relaciones afectivas y toma de decisiones en niños/niñas. Convicciones y conductas sobre virginidad. Significado y valor de acuerdo con las diferencias generacionales. Percepción sobre el concepto, situación y vulneración de los derechos humanos en el departamento de Santander, Colombia. Factores que influyen en la vulnerabilidad frente al delito de la trata de personas en estudiantes universitarios de la Universidad Cooperativa de Colombia. Violencia intrafamiliar desde la perspectiva del agresor: un estudio de caso en la cárcel de máxima seguridad de Palogordo de Bucaramanga