Genome sequences of triacylglycerol metabolism in Rhodococcus as a platform for comparative genomics

Bacteria belonging to the Rhodococcus genus are usually able to synthesize and accumulate variable amounts of triacylglycerols (TAG) from diverse carbon sources. Although some significant advances in the basic knowledge on TAG metabolism in rhodococci have been made, the fundamental understanding of this process and its regulation remains to be clarified. The abundantly available genomic information for several rhodococcal species provides the possibility for comparative genome analysis on the occurrence and distribution of key genes and pathways involved in TAG metabolism. Our bioinformatic analyses of available databases from six rhodococcal strains demonstrated that genes/enzymes for reactions related to TAG biosynthesis and degradation, and fatty acid β-oxidation are surprisingly abundant in rhodococcal genomes. Several genes/enzymes of glycerolipids and fatty acid metabolism are highly represented in the analyzed genomes. A number of previously undescribed, new putative genes for glycerolipid metabolism in rhodococci have been identified and the size of each family has been estimated

El conocimiento científico producido en la UNC sobre COVID-19, recopilado en un repositorio digital de acceso abierto

Con más de 150 artículos publicados, la Colección COVID-19 del Repositorio Digital de la Universidad Nacional de Córdoba recoge los abordajes científicos y tecnológicos más recientes en torno a la crisis sanitaria provocada por el coronavirus. Este espacio reúne las producciones de grupos de investigación de distintos campos disciplinares, no solo de los relativos a la salud, y ofrece la posibilidad de consultar libre y gratuitamente información de calidad y utilidad para comprender mejor los alcances e implicancias de la pandemia. Para enviar documentos a la Oficina de Conocimiento para ser publicados en el RDU: [email protected]: Villalba, María José. Universidad Nacional de Córdoba. Prosecretaría de Comunicación Institucional. UNCiencia; Argentina.Fil: Nardi, Alejandra M. Universidad Nacional de Córdoba. Área de Gestión Institucional. Oficina de Conocimiento Abierto, Argentina

Metabolism of triacylglycerols in Rhodococcus species: insights from physiology and molecular genetics

Rhodococcus bacteria possess the ability to accumulate variable amounts of triacylglycerols (TAG) during growth on diverse carbon sources. The evolution seems to have selected these microorganisms as specialists in the accumulation of TAG among bacteria, since their biochemistry is efficiently designed for the biosynthesis and mobilization of these lipids. Detailed research of rhodococcal TAG metabolism started only a few years ago; thus, the fundamental understanding of this process and its regulation remains to be clarified. However, some interesting advances in the basic knowledge on TAG metabolism in rhodococci have been made. Most studies have focused on the physiology of TAG biosynthesis and mobilization in rhodococci. Only recently, some advances in molecular biology and genetics on TAG metabolism occurred as a result of the increasing available genomic information and the development of new genetic tools for rhodococci. These studies have been focused principally on some enzymes of TAG biosynthesis, such as the wax esters/diacylglycerolacyltransferases (WS/DGAT) and TAG granule-associated proteins. In this context, the most relevant achievements of basic research in the field have been summarized in this review article

7-Nitroindazole down-regulates dopamine/DARPP-32 signaling in neostriatal neurons in a rat model of Parkinson's disease

Neuronal nitric oxide synthase (nNOS) is involved in the regulation of diverse intracellular messenger systems in the brain. Nitric Oxide (NO) contributes to inducing signaling cascades that involve a complex pattern of phosphorylation of DARPP-32 (in Thr-34), which controls the phosphoproteins involved in neuronal activation. However, the role of NO in the pathophysiology of Parkinson's disease (PD) and its effect in striatal neurons have been scarcely explored. In the present work, we investigate the effects of a nitric oxide synthase (NOS) inhibitor, 7-nitroindazole (7-NI) in the nigrostriatal pathway of striatal 6-hydroxydopamine (6-OHDA) lesioned rats. Our quantitative histological findings show that treatment with 7-NI significantly reduced 6-OHDA-induced dopaminergic damage in the dorsolateral striatum and Substantia Nigra pars compacta (SNpc). Moreover, 6-OHDA lesioned rats show a significant increase of nNOS+ and Phospho-Thr34-DARPP-32+ cells, accompanied by a consequent decrease of total DARPP-32+ cells, which suggests an imbalance of NO activity in the DA-depleted striatum, which is also reflected in behavioral studies. Importantly, these effects are reverted in the group treated with 7-NI. These results show a clear link between the state of phosphorylation of DARPP-32 and parkinsonism, which is regulated by nNOS. This new evidence suggests a prominent role for nitric oxide in the neurotransmitter balance within the basal ganglia in the pathophysiology of experimental parkinsonism.This work was supported by grants from the Spanish Ministry of Science (SAF 2007-62262), FIS (PI/2010/02827) and CIBERNED (Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas)

Insights into the metabolism of oleaginous Rhodococcus spp

Some species belonging to the Rhodococcus genus, such as Rhodococcus opacus, R. jostii, and R. wratislaviensis, are known to be oleaginous microorganisms, since they are able to accumulate triacylglycerols (TAG) at more than 20% of their weight (dry weight). Oleaginous rhodococci are promising microbial cell factories for the production of lipids to be used as fuels and chemicals. Cells could be engineered to create strains capable of producing high quantities of oils from industrial wastes and a variety of high-value lipids. The comprehensive understanding of carbon metabolism and its regulation will contribute to the design of a reliable process for bacterial oil production. Bacterial oleagenicity requires an integral configuration of metabolism and regulatory processes rather than the sole existence of an efficient lipid biosynthesis pathway. In recent years, several studies have been focused on basic aspects of TAG biosynthesis and accumulation using R. opacus PD630 and R. jostii RHA1 strains as models of oleaginous bacteria. The combination of results obtained in these studies allows us to propose a metabolic landscape for oleaginous rhodococci. In this context, this article provides a comprehensive and integrative view of different metabolic and regulatory attributes and innovations that explain the extraordinary ability of these bacteria to synthesize and accumulate TAG. We hope that the accessibility to such information in an integrated way will help researchers to rationally select new targets for further studies in the field.Fil: Alvarez, Héctor M.. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; ArgentinaFil: Herrero, O. Marisa. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; ArgentinaFil: Silva, Roxana A.. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; ArgentinaFil: Hernández, Martín A.. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; ArgentinaFil: Lanfranconi, Mariana Patricia. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; ArgentinaFil: Villalba, María Soledad. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; Argentin

La formación de maestros de CABA: motivaciones, expectivas y perfeccionamiento

El presente estudio se centra en dos aspectos de la figura del docente primario: su formación y los problemas en el desempeño de su tarea en la actualidad. Ambas cuestiones son relevantes para el análisis de uno de los actores sociales más cuestionados dentro de los considerados problemas de la educación. Los estudios concluyen que existe insuficiente preparación, así como falta de motivación en lo que respecta a su desempeño laboral. El propósito de la investigación es elucidar si tanto desde la formación de los futuros maestros, como en el desempeño de docentes que llevan más de cinco años en ejercicio, pueden confirmarse esos resultados. Con la aspiración de avanzar en la línea de estudios realizados por Emilio Tenti Fanfani, la investigación tuvo dos objetivos generales: analizar el perfil de los estudiantes del profesorado de nivel inicial, en institutos públicos y privados de CABA, en 2015; y estudiar los criterios que sigue la formación de los docentes primarios, a partir de las trayectorias relatadas por ellos mismos. Se aplicaron encuestas y entrevistas en profundidad a estudiantes de profesorado de nivel primario ya docentes en ejercicio de tres instituciones de Ciudad Autónoma de Buenos Aires que cuentan con escuelas y profesorados de nivel primario: Normal 4, Instituto San Cayetano y María Auxiliadora. Las tres instituciones fueron elegidas pues se las considera importantes en cuanto a: la cantidad de alumnos, la trayectoria y el prestigio. Como resultado de las noventa y nueve encuestas a estudiantes de profesorado y de las dieciséis entrevistas a docentes en ejercicio, se pudo dilucidar que más de la mitad de los primeros se encuentran en ejercicio por la gran demanda del mercado laboral y que se muestran preocupados por sus alumnos, la mayoría de ellos afectados por problemas que aparecen en este entramado social cada vez más complejo. Por otro lado, los docentes son conscientes del desafío que abordan y de las limitaciones que enfrentan, pero muestran un espíritu altruista y se comprometen con las intenciones que los llevaron a su vocación. Buscan en la capacitación herramientas que los preparen para comprender e interveniren los problemas que les afectan a los niños y sus familias. El rol del docente se ha convertido en el de un agente resocializador de los niños y sus familias dentro de los nuevos problemas sociales.Tanto unos como los otros reconocen que la preparación que reciben es insuficiente para las problemáticas que se presentan cotidianamente en las aulas de las instituciones educativas públicas y privadas.This study focuses on two aspects of the figure of primary teachers: their training and problems in performing their task today. Both relevant to the analysis of one of the most questioned social actors within the considered problems of education issues. Studies speak of insufficient preparation thereof and lack of motivation for their job performance. The purpose of the research is to elucidate whether these concepts can be sustained through a new analysis, both the training of future teachers and teacher performance carrying more than five years in exercise. Aspiring to advance the line of studies by Emilio Tenti Fanfani, the research had two main objectives: to analyze the profile of student’s faculty initial level in public and private institutes of CABA in 2015 and study the way that follows the training of primary teachers from the paths reported by themselves. Surveys and interviews were applied in student teachers at the primary level and practicing teachers, three institutions of Buenos Aires that have primary schools and professorships: Normal 4, San Cayetano and Maria Auxiliadora‘s Institutes. The three institutions were chosen for different aspects such as: number of students, experience and prestige. As a result of the ninety nine surveys student teachers and sixteen interviews with practicing teachers, it was elucidated that more than half of the former are in the exercise by the high demand of the labor market and are concerned about their students, most of them affected by problems encountered in this increasingly complex social network. On the other hand teachers are aware of the challenge and addressing the constraints they face, but show an altruistic spirit and committed to the intentions that led to his vocation. They browsed training tools to prepare them to understand and intervene in the problems that affect children and their families. The teacher’s role has become an agent re-socializing children and their families within the new social problems. Both groups recognize that other preparation they receive is insufficient for the problems that arise daily in the classrooms of public and private educational institutions

Metalloproteinase-9 contributes to inflammatory glia activation and nigro-striatal pathway degeneration in both mouse and monkey models of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinsonism

Inflammation is a predominant aspect of neurodegenerative diseases, manifested by glia activation and expression of pro-inflammatory mediators. Studies on animal models of Parkinson’s disease (PD) suggest that sustained neuroinflammation exacerbates degeneration of the dopaminergic (DA) nigro-striatal pathway. Therefore, insights into the inflammatory mechanisms of PD may help the development of novel therapeutic strategies against this disease. As extracellular matrix metalloproteinases (MMPs) could be major players in the progression of Parkinsonism, we investigated, in the substantia nigra and striatum of mice acutely injected with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), changes in mRNA expression, protein levels, and cell localization of MMP-9. This protease is mainly neuronal, but early after MPTP injection its mRNA and protein levels, as well as the number of MMP-9-expressing microglia and astrocytes, increase concomitantly to a prominent inflammation. Neuroinflammation and MMP-9+ glia begin to decline within 2 weeks, although protein levels remain higher than control, in association with a partial recovery of DA nigro-striatal circuit. Comparable quantitative studies on MMP-9 knock-out mice, show a significant decrease in both glia activation and loss of DA neurons and fibers, with respect to wild-type. Moreover, in a parallel study on chronically MPTP-injected macaques, we observed that perpetuation of inflammation and high levels of MMP-9 are associated to DA neuron loss. Our data suggest that MMP-9 released by injured neurons favors glia activation; glial cells in turn reinforce their reactive state via autocrine MMP-9 release, contributing to nigro-striatal pathway degeneration. Specific modulation of MMP-9 activity may, therefore, be a strategy to ameliorate harmful inflammatory outcomes in Parkinsonism

Aceleraciones registradas y calculadas del sismo del 12 de agosto de 2014 en Quito.

El 12 de agosto de 2014, se registró un sismo de magnitud 5.1, a una profundidad focal de 4 km., en el segmento de falla Bellavista Catequilla, el mismo que fue registrado en 8 estaciones localizadas en la ciudad de Quito. Estas se encuentran ubicadas a distancias epicentrales entre 12 y 19 km. En este artículo se comparan las aceleraciones máximas obtenidas en campo libre, con las que se obtienen al emplear las ecuaciones de movimientos fuertes de Campbell y Borzognia (2013) y el de Zhao et al. (2006). Para ello previamente se determina un plano de ruptura del sismo, utilizando las ecuaciones propuestas por Leonard (2010) y la geometría de las fallas ciegas propuestas por Alvarado (2014). ABSTRACT: On August 12 th 2014, a magnitude 5.1 earthquake occurred at a depth of 4 km, in the Bellavista Catequilla fault segment. This event was recorded by 8 strong-motion stations located between 12 and 19 km from the epicenter, in the city of Quito. In this article, the maximum ground accelerations recorded in free field are compared with the accelerations estimated using the models by Campbell y Borzognia (2013) and Zh ao et al. (2006). To this end, the earthquake rupture plane is determined using the equations proposed by Leonard (2010) and the geometry of the blind fault system of Quito proposed by Alvarado (2014)