Screen of Nuclear Localized Effecters Proteins in Coxiella burnetii

In some pathogens such as Ehrlichia chaffeensis, Anaplasma phagocytophilum, Chlamydia, and Shigella, secreted effector proteins have been found to localize to the nucleus and alter the host’s immune response by modulating chromatin or binding to regulatory transcription molecules. By doing so, the pathogen is able to successfully grow and replicate within the host cell causing infection. Several of Coxiella burnetii’s secreted effector proteins have similarly been found to localize to the nucleus but have no confirmed role. The objective of this study is to confirm nuclear localization of previously identified nuclear effector proteins and pinpoint any interactions between host DNA and protein. Each GFP tagged effector protein of interest- CBU0129, CBU0794, CBU0393, CBU1314, and CBU1524, was ectopically expressed in HeLa cells to perform sub-cellular fractionation. These sub-cellular fractions were run on a SDS-Page gel and probed with anti-GFP to identify any association with specific fractions within the host. Nuclear localization signal (NLS) truncations were then constructed using splicing by overlap-extension PCR (SOEing PCR) to remove predicted nuclear localization signals from each effector. The ΔNLS constructs were also ectopically expressed in HeLa cells to visualize loss of localization. Chromatin Immunoprecipitation (ChIP) was performed to identify specific binding regions of each protein and further studies such as en Electrophoretic Mobility Shift Assay (EMSA) were attempted to confirm the binding of chromatin by the effector proteins. Sub-cellular fractionation confirmed the association of all five effector proteins to host chromatin, and the loss of nuclear localization by two effectors upon deletion of predicted NLS indicates that these effectors are not only specifically imported to the nucleus via NLS, but have some specialized role in the nucleus. Confirmation of these predicted protein-DNA interactions will allow Coxiella researchers to better understand how this organism survives and replicates. With more knowledge of these processes, scientists will be better equipped to prevent and treat future infections

Mecanismos de adsorción y acumulación intracelular de Pb²⁺ en Salvinia minima

La fitorremediación es una tecnología ambientalmente pertinente que ha resultado muy útil como método alternativo a las tecnologías convencionales, para el tratamiento de aguas residuales. Dentro de este contexto, los sistemas con plantas acuáticas han demostrado ser eficientes para eliminar metales. En estudios previos se encontró que la adsorción y la acumulación intracelular, en ausencia de nutrientes, son los principales mecanismos de eliminación de Pb2+ por Salvinia minima en sistemas de lagunas operadas por lote. Asimismo, se demostró que este helecho acuático es hiperacumulador de Pb2+ (Olguín et al., 2005). Sin embargo, es necesario generar más conocimiento para entender los mecanismos básicos participantes en la hiperacumulación del metal, lo que permitirá coadyuvar en la optimización de las fitotecnologías para el tratamiento de efluentes que utilizan plantas hiperacumuladoras. El presente trabajo es una contribución al conocimiento de algunos de los factores y mecanismos participantes en la hiperacumulación de Pb2+ en Salvinia minima a diferentes niveles, lo que coadyuvará en la evaluación de la hiperacumulación de metales en otras plantas de este tipo. Se describen por primera vez las características fisicoquímicas de Salvinia minima siendo, el área superficial (264 m²/g) y el contenido de grupos carboxilo (0.95 mmol/H+), dos de las más importantes en la acumulación de metales. Se determinó y evaluó la hiperacumulación de Pb2+ en un amplio intervalo de concentraciones iniciales (Ci) de Pb2+ (0.8±0.00, 2.70±0.03, 4.70±0.06, 15.18±0.55 y 28.40±0.22 mg Pb2+/L) y tiempos de exposición (0.5,2,4,6,8 y 24 h) en presencia de ciertos compuestos orgánicos e inorgánicos (ácido propiónico y sulfato de magnesio). Basado en un análisis de compartamentalización, se propusieron dos factores novedosos tales como el factor de adsorción (FAD) y el factor de acumulación intracelular (FAI) para obtener un mayor entendimiento sobre la hiperacumulación de Pb2+ en la planta. Este proceso se debe principalmente a la adsorción (FAD en el intervalo de 780 a 1980), resultado de sus extraordinarias características fisicoquímicas. Asimismo, se encontró que el Pb2+ fue acumulado intracelularmente a Ci tan altas como 28.40±0.22 mg Pb2+/L (FAI en el intervalo de 57 a1007). Además, se presenta un análisis cinético de dichos mecanismos a partir del cual la quimioadsorción fue inferida como el mecanismo específico responsable de la adsorción de Pb2+, de acuerdo al modelo de adsorción de pseudo-segundo orden. La acumulación intracelular también contribuyó a la hiperacumulación de Pb2+ en S. minima y parece estar descrita por el modelo de Michaelis-Menten.Phytoremediation is an environmentally sound technology that has shown to be very efficient for the treatment of wastewaters. Treatment systems using aquatic plants have proven to be efficient to remove metals. Previously, it was found that the main Pb2+ removal mechanism, in batch-operated lagoons with Salvinia minima, was adsorption, followed by intracellular accumulation. Furthermore, S.minima was shown to be a Pb2+ hyperaccumulator (Olguín et al., 2005). However, more information is required to understand the mechanisms involved in metal hyperaccumulation and to contribute to the optimization of phytotechnologies using hyperaccumulating plants. This work is a contribution to understand some factors and mechanisms involved in the Pb2+ hyperaccumulation, in Salvinia minima at different levels, which will be very useful for the metal hyperaccumulation assessment in other plants of this type. The physico-chemical characteristics of the plant are presented. A high specific surface (264 m²/g) and a high content of carboxylic groups (0.95 mmol/H+) were found. Pb2+ hyperaccumulation was tested using a wide range of metal initial concentration (Ci) (0.8±0.00, 2.70±0.03, 4.70±0.06, 15.18±0.55 and 28.40±0.22 mg Pb2+/L) and exposure time (0.5, 2,4,6,8 and 24 h) in the presence and absence of some organic and inorganic compounds (propionic acid and magnesium sulfate). Based on a compartmentalization analysis, a bioadsorption (BAF) and an intracellular accumulation factor (IAF) were proposed to obtain an indepth insight into the Pb2+ hyperaccumulation in S. minima. The main mechanism during such process was adsorption (BAF ranged from 780 to1980) and according to the pseudo-second order adsorption model, chemisorption was predicted to play a major role. Surprisingly, it was found that Pb2+ was accumulated into the cells of the plant at a Ci as high as 28.40±0.22 mg Pb2+/L (IAF ranged from 5 to 1007). The intracellular accumulation of Pb2+ in S. minima seems to be described by Michaelis-Menten model

La imagen y la narrativa como herramientas para el abordaje psicosocial en escenarios de violencia Apartado, El Peñol, Medellín Y Turbo Antioquia.

La violencia social en Colombia marcó a muchas personas de diversas formas, dejando muertes, desplazamientos, heridas, discapacidades físicas, familias y una sociedad con huellas profundas de temor, sufrimiento y con otra gran cantidad de problemas sociales como: desigualdad, pobreza, discriminación narcotráfico, corrupción, desempleo, entre otros. Desde hace algún tiempo se tiene en cuenta la intervención y el enfoque psicosocial como el mejor mecanismo para trasformar estas realidades, en el tratamiento de los efectos traumáticos que se produjeron con el conflicto armado, apuntando a una atención integral, para las víctimas; por lo que se hace indispensable que todos los profesionales que aborden problemáticas relacionadas con escenarios de violencia propongan estrategias que mitiguen los daños causados por la vulneración de los derechos fundamentales y que permitan identificar habilidades sociales para el afrontamiento y superación del sufrimiento de las víctimas. En la realización del paso 4 se analizan casos y relatos de vida desde una mirada psicológica tomados del libro, Voces: Relatos de violencia y esperanza en Colombia, sobre algunos hechos violentos traumáticos; se identifican aquellos emergentes e impactos psicosociales presentados en cada uno de los contextos e historias narradas. Así mismo se abordan aquellas intersubjetividades y subjetividades que rodean a las víctimas reconociendo sus relaciones, sus costumbres, cultura y sobre todo sus emociones. Se proponen estrategias psicosociales como alternativas para disminuir los daños causados por la violencia. La narrativa como instrumento para abordar realidades y escenarios de violencia, favorece la compresión de los hechos, púes las personas toman voz para expresar a su manera las experiencias y vivencias que se tornaron alrededor de cada relato o suceso. Así mismo con la narrativa se contribuye al empoderamiento de las víctimas a través del fomento de capacidades de resistencia y afrontamiento a las adversidades. Compartir la experiencia de este último trabajo del diplomado, nos ha llevado a reflexionar sobre la labor y rol de los profesionales de psicología a la hora de intervenir con este tipo de poblaciones, pues sobre nosotros recae una gran responsabilidad que es la de ser agentes de cambios, dinamizadores de procesos reparadores y fortalecedores, comprendiendo el comportamiento, los distintos contextos y reconociendo las individualidades de cada persona condición de víctima.The social violence in Colombia marked many people in different ways, leaving deaths, displacements, wounds, physical disabilities, families and a society with deep traces of fear, suffering and another large number of social problems such as: inequality, poverty, drug trafficking , corruption, unemployment, among others. For some time now, intervention and the psychosocial approach have been taken into account as the best mechanism to transform these realities, in the treatment of the traumatic effects that occurred with the armed conflict, aiming at an integral attention, for the victims; Therefore, it is essential that all professionals who address problems related to violence scenarios propose strategies that mitigate the damage caused by the violation of fundamental rights and that allow identifying social skills for coping and overcoming the suffering of victims. In the realization of step 4, cases and life stories are analyzed from a psychological perspective taken from the book, Voices: Stories of violence and hope in Colombia, about some violent traumatic events; identify emerging and psychosocial impacts presented in each of the contexts and stories told. Likewise, those intersubjectivities and subjectivities that surround the victims are addressed, recognizing their relationships, their customs, culture and especially their emotions. Psychosocial strategies are proposed as alternatives to reduce the damage caused by violence. The narrative as an instrument to deal with realities and scenarios of violence, favors the understanding of the facts, because people take a voice to express in their own way the experiences and experiences that became around each story or event. Likewise, the narrative contributes to the empowerment of the victims through the promotion of resilience and coping skills

Identification of Coxiella burnetii Type IV Secretion Substrates Required for Intracellular Replication and Coxiella-Containing Vacuole Formation

Coxiella burnetii, the etiological agent of acute and chronic Q fever in humans, is a naturally intracellular pathogen that directs the formation of an acidic Coxiella-containing vacuole (CCV) derived from the host lysosomal network. Central to its pathogenesis is a specialized type IVB secretion system (T4SS) that delivers effectors essential for intracellular replication and CCV formation. Using a bioinformatics-guided approach, 234 T4SS candidate substrates were identified. Expression of each candidate as a TEM-1 β-lactamase fusion protein led to the identification of 53 substrates that were translocated in a Dot/Icm-dependent manner. Ectopic expression in HeLa cells revealed that these substrates trafficked to distinct subcellular sites, including the endoplasmic reticulum, mitochondrion, and nucleus. Expression in Saccharomyces cerevisiae identified several substrates that were capable of interfering with yeast growth, suggesting that these substrates target crucial host processes. To determine if any of these T4SS substrates are necessary for intracellular replication, we isolated 20 clonal T4SS substrate mutants using the Himar1 transposon and transposase. Among these, 10 mutants exhibited defects in intracellular growth and CCV formation in HeLa and J774A.1 cells but displayed normal growth in bacteriological medium. Collectively, these results indicate that C. burnetii encodes a large repertoire of T4SS substrates that play integral roles in host cell subversion and CCV formation and suggest less redundancy in effector function than has been found in the comparative Legionella Dot/Icm model

SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2–4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Inventario de Sexismo Ambivalente (ISA) en adolescentes chilenos: estructura factorial, fiabilidad, validez e invarianza por sexo

Ambivalent Sexism Inventory (ASI) in Chilean adolescents: Factor structure, reliability, validity and sex invariance. Ambivalent sexism is a multidimensional construct conformed by hostile and benevolent beliefs and attitudes that tend to legitimize each other justifying male structural power. Sexism studies in adolescent population become relevant as it is a fundamental evolutive stage for settle gender relations beliefs. However, the tools that measures sexist representations in adolescents are scarce. The main goal was to evaluate the psychometric properties of the Ambivalent Sexism Inventory (ASI) in Chilean adolescents, and analyze invariance by sex. Sample was composed of 546 students between 15–18 years (M= 15.52; SD=.66), of which 58.8% were women. Exploratory factor analyses and confirmatory factor analyses were the method of the study. The results of the exploratory factor analyses suggested to hold back the 20 items from the original structure grouped in two factors. Confirmatory factor analyses results showed suitability of the two factors theoretical proposal, hostile sexism and benevolent sexism (χ2 (166) = 302.34; CFI = .99; TLI = .98; RMSEA = .05; SRMR = .07), which includes benevolent sexism as a second-order factor conformed by three subcomponents (protective paternalism, complementary gender differentiation, and heterosexual intimacy). The factorial structure of the selected model explained 56% of the total variance. The reliability of the ASI reached a satisfactory levels of ordinal alpha (αordinal = .93) for the complete instrument and the correlation analyses provide evidences of discriminant validity. The Invariance factorial analyses showed that the equivalence level of the ASI is plausible in the strict level. It is concluded that the ASI presents adequate psychometric properties for its use in Chilean adolescent population.El sexismo ambivalente es un constructo multidimensional compuesto por creencias y actitudes hostiles y benévolas que se legitiman entre sí para justificar el poder masculino estructural. Los estudios sobre sexismo en adolescentes cobran relevancia al ser una etapa evolutiva fundamental para asentar creencias acerca de las relaciones de género. Sin embargo, los instrumentos para medir representaciones sexistas en este grupo son escasos. Este estudio evaluó las propiedades psicométricas del Inventario de Sexismo Ambivalente (ISA) en adolescentes chilenos, concretamente se analizó la estructura factorial y su fiabilidad, validez e invarianza factorial por sexo. La muestra estuvo conformada por 546 estudiantes entre 15 y 18 años (M=15.52; DT=.66), de los cuales el 58.8% fueron mujeres. Los métodos que se utilizaron fueron Análisis Factorial Exploratorio y Análisis Factorial Confirmatorio. El resultado del análisis exploratorio sugirió retener los 20 ítems de la escala original agrupados en dos factores. Los resultados del análisis confirmatorio corroboraron la estructura original de la escala y precisaron un modelo de dos factores correlacionados, Sexismo Hostil y Sexismo Benévolo (χ2 (166) = 302.34; CFI = .99; TLI = .98, RMSEA = .05, SRMR = .07), que considera al Sexismo Benévolo como un factor de segundo orden con tres subcomponentes (Paternalismo Protector, Intimidad Heterosexual y Diferenciación de Género). El modelo seleccionado coincidió con la propuesta teórica y explicó el 56% de la varianza. El análisis de fiabilidad indicó un alfa ordinal total de 0.93 y el análisis correlacional demostró evidencia de validez discriminante. El análisis de invarianza factorial evidenció que el grado de equivalencia del instrumento por sexo es plausible a un nivel estricto. Se concluyó que el ISA presenta adecuadas propiedades psicométricas para su uso en adolescentes de Chil