ASF1 Proteins are Involved in UV-induced DNA Damage Repair and are Cell Cycle Regulated by E2F Transcription Factors in Arabidopsis thaliana

ASF1 is a key histone H3/H4 chaperone that participates in a variety of DNA and chromatin-related processes, including DNA repair, where chromatin assembly and disassembly is of primaryrelevance. Information concerning the role of ASF1 proteins in post-UV response in higher plants is currently limited. In Arabidopsis thaliana, an initial analysis of in vivo localization of ASF1A andASF1B indicates that both proteins are mainly expressed in proliferative tissues. In silico promoteranalysis identified ASF1A and ASF1B as potential targets of E2F transcription factors. Theseobservations were experimentally validated, both in vitro by electrophoretic mobility shift assays, and in vivo by chromatin immunoprecipitation assays and expression analysis using transgenic plants with altered levels of different E2F transcription factors. These data suggest that ASF1A and ASF1B are regulated during cell cycle progression through E2F transcription factors. In addition, we found that ASF1A and ASF1B are associated with the UV-B induced DNA damage response in A. thaliana. Transcript levels of ASF1A and ASF1B were increased following a UV-B-treatment. Consistent with a potential role in ultraviolet-B (UV-B) response, RNAi silenced plants of both genes showed increased sensitivity to UV-B compared to wild type plants. Finally, by coimmunoprecipitation analysis, we found that ASF1 physically interacts with N-terminal acetylated histones H3 and H4, and with acetyltransferases of the HAM subfamily, which are known to be involved in cell cycle control and DNA repair, among other functions. Together, here we provide evidence that ASF1A and ASF1B are regulated by cell cycle progression and are involved in DNA repair after UV-B irradiation.Fil: Lario, Luciana Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro de Estudios Fotosintéticos y Bioquímicos (i); ArgentinaFil: Gutierrez, Crisanto. Universidad Autónoma de Madrid; EspañaFil: Ramirez Parra, Elena. Universidad Politecnica de Madrid; EspañaFil: Spampinato, Claudia Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro de Estudios Fotosintéticos y Bioquímicos (i); ArgentinaFil: Casati, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro de Estudios Fotosintéticos y Bioquímicos (i); Argentin

Auxin and epigenetic regulation of SKP2B, an F-box that represses lateral root formation

In plants, lateral roots originate from pericycle founder cells that are specified at regular intervals along the main root. Here, we show that Arabidopsis (Arabidopsis thaliana) SKP2B (for S-Phase Kinase-Associated Protein2B), an F-box protein, negatively regulates cell cycle and lateral root formation as it represses meristematic and founder cell divisions. According to its function, SKP2B is expressed in founder cells, lateral root primordia and the root apical meristem. We identified a novel motif in the SKP2B promoter that is required for its specific root expression and auxin-dependent induction in the pericycle cells. Next to a transcriptional control by auxin, SKP2B expression is regulated by histone H3.1/H3.3 deposition in a CAF-dependent manner. The SKP2B promoter and the 59 end of the transcribed region are enriched in H3.3, which is associated with active chromatin states, over H3.1. Furthermore, the SKP2B promoter is also regulated by H3 acetylation in an auxin-and IAA14-dependent manner, reinforcing the idea that epigenetics represents an important regulatory mechanism during lateral root formation

Juntos y Saludables: Outcomes of a peer led approach to obesity prevention for Head Start

Purpose: The purpose of this study was to evaluate Juntos y Saludables (Get Healthy Together), a multi-component obesity prevention pilot tailored for Mexican American Head Start children (ages 3-5). For the parent education component, researchers trained seven peer parent educators to deliver health information via afterschool parent education sessions. When parents attended the sessions, they received a take-home bag with a book and family activity to promote physical activity in the home. Method: Parent intercept interviews, focus groups, and questionnaires were collected (average 80% participation rate). Results: Average participation rate at the parent education sessions was 46% and rates varied between 34% (61 parents) and 53% (94 parents). More parents in the intervention school reported that their child ate fruit at least 3 times (83.5% versus 79.17%), ate in front of the television less than three times (70.87% versus 49.38%) during the typical week and more parents reported that their child watched 2 hours or less of television each day (73.79% versus 13.19%), compared to the comparison school. 81% of parents interviewed correctly identified the program name. On average, parents could recall almost 3 (M=2.94, SD=1.92) of the 8 key messages without a prompt and about 6 (M=5.91, SD=1.88) when prompted. Messages recalled the most, without a prompt, included (1) preschoolers need 60 minutes of physical activity each day, and (2) children who get all five servings of fruits and vegetables each day are more likely to get the nutrients they need. In the focus group, parents reported that they enjoyed the peer-led session format and session scheduled time. Conclusion: Results suggest that peer-led approaches can be highly effective with parents, especially when addressing childhood obesity prevention

Immunoreactive proteins of Trypanosoma vivax

Bovine trypanosomosis, caused by Trypanosoma vivax has a significant negative impact on livestock. This research was performed with the aim of determining the immunoreactive proteins present in T. vivax. Thus, five sheep were experimentally infected with T. vivax TvZC1 isolate. Animal number 1 was used as the source of the trypanosomes and to prepare the soluble extract of parasites. Sheep numbers 2 to 5 were monitored for eight weeks and sera was obtained every two weeks for immunodetection. Parasites obtained from animal 1 were analyzed for T. vivax proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot (WB). The WB analysis showed three immunodominant proteins with a molecular mass of 42, 64 and 72 kDa, approximately. The 64 kDa protein was recognized by every animal during the complete infection period. The 72 kDa protein only was detected by animals 2, 3 and 5 during the infection course, whereas in animal 4 it was only detected during the 6th and 8th weeks post infection. Moreover, the 42 kDa polypeptide was slightly immunorecognized by animals 2, 3 and 4 during the complete infection period, but in animal 5 only it was identified during the 2nd week post infection. It is assumed that the 42 kDa protein is the VSG of T. vivax, which resulted in a low antigenic capacity, contrary to the protein of 64 kDa which showed a high antigenic capacity and cross-reactivity with Trypanosoma evansi. (Résumé d'auteur

Lessons Learned from Juntos Y Saludables Peer-Led Parent Education

Purpose: The objective of this study was to assess the quality of training received by peer educators in the Juntos y Saludables (Get Healthy Together) program. Juntos y Saludables is a multi-component childhood obesity prevention program for Head Start. Method: This study applied the peer led education approach to provide parents with education regarding healthy growth among their children. Seven parents were recruited through teachers, other parents, and the Parent Leadership Institute at a local Head Start center. Faculty and graduate assistants from local universities provided training to the parent educators in both English and Spanish. Training sessions were conducted the week of each new parent education session, with one booster training after spring break (7 training sessions in total). The parent educators were trained to: (1) encourage the Head Start parents to participate in the sessions, (2) explain the health messages, and (3) answer any questions the parents had. A focus group was conducted at the end of the program, with all seven parent educators, to assess their feedback about the training they received. Results: The peer parent educators reported that they became educators to improve children’s health. They were satisfied with the training methods and felt that they learned a lot of information regarding nutrition and physical activity recommendations for their children. They also reported feeling comfortable delivering health information to other parents. Parent educators appreciated that they could work together (e.g., in bilingual pairs) to provide the health education to parents in both English and Spanish. The peer parent education training session attendance was high-71% and greater. Conclusions: Most peer parent educators felt comfortable and confident delivering the material as the program progressed. Earlier training might assist the parent educators to have greater familiarity with content prior to the first session. Educators also created strategies to deal with situations that arose during the sessions (e.g. crowd control, parents requesting extra bags). Future training can include suggested strategies to handle similar situations

Trypanosoma vivax infection in sheep: Different patterns of virulence and pathogenicity associated with differentially expressed proteomes

Cattle trypanosomosis caused by Trypanosoma vivax is a widely distributed disease in Africa and Latin America. It causes significant losses in the livestock industry and is characterized by fluctuating parasitemia, anemia, fever, lethargy, and weight loss. In this study we evaluated the virulence (capacity to multiply inside the host and to modulate the host response) and pathogenicity (ability to produce disease and/or mortality) patterns of two T. vivax strains (TvMT1 and TvLIEM176) in experimentally-infected sheep and determined the proteins differentially expressed in the proteomes of these two strains. Hematological and clinical parameters were monitored in experimentally-infected versus non-infected sheep for 60 days. All the infected animals developed discernable parasitemia at 3 days post-infection (dpi), and the first parasitemia peak was observed at 6 dpi. The maximum average value of parasitemia was 1.3 × 107 (95% CI, 7.9 × 105–2 × 108) parasites/ml in TvLIEM176-infected animals, and 2.5 × 106 (95% CI, 1.6 × 105–4 × 107) parasites/ml in TvMT1-infected ones. Anemia and clinical manifestations were more severe in the animals infected by TvMT1 strain than in those infected by TvLIEM176. In the proteomic analysis, a total of 29 proteins were identified, of which 14 exhibited significant differences in their expression levels between strains. Proteins with higher expression in TvLIEM176 were: alpha tubulin, beta tubulin, arginine kinase, glucose-regulated protein 78, paraflagellar protein 3, and T-complex protein 1 subunit theta. Proteins with higher expression in TvMT1 were: chaperonin HSP60, T-complex protein 1 subunit alpha, heat shock protein 70, pyruvate kinase, glycerol kinase, inosine-5'-monophosphate dehydrogenase, 73 kDa paraflagellar rod protein, and vacuolar ATP synthase. There was a difference in the virulence and pathogenicity between the T. vivax strains: TvLIEM176 showed high virulence and moderate pathogenicity, whereas TvMT1 showed low virulence and high pathogenicity. The proteins identified in this study are discussed for their potential involvement in strains' virulence and pathogenicity, to be further defined as biomarkers of severity in T. vivax infections

Responsabilidad Social y Ciudadanía: Una perspectiva desde la universidad y la administración pública

La importancia de los estudios sobre ciudadanía se vincula con la imperiosa necesidad de fortalecer la democracia en todos aquellos espacios donde se manifiesta, principalmente en países como México, donde la falta de credibilidad en las instituciones democráticas ha permeado a la sociedad.Los desafíos contemporáneos requieren nuevos ajustes en diversos sentidos; al interior de las organizaciones es necesario adecuar los mecanismos con que interactúan frente a la sociedad en la que se desarrollan. Es requisito indispensable que el grueso de las organizaciones sociales se vinculen de manera directa con los problemas globales y nacionales: cambio climático, guerras, exigencias democráticas, movimientos sociales, pobreza, desempleo, inestabilidades políticas etc., ello les exige que se asuman como parte del complejo social, donde sus acciones repercuten de forma directa o indirecta

Evaluación de efectos antitumorales de un oligonucleótido (ODN) tipo señuelo dirigido a STAT3 en un modelo de línea celular de cáncer de pulmón

Resumen: Actualmente el cáncer continúa siendo una enfermedad con altas tasas de incidencia y mortalidad a nivel mundial. El desarrollo de nuevas moléculas para tratar los diferentes tipos de cáncer se encuentra enfocado en la terapia molecular dirigida. Sin embargo, pocas estrategias de este tipo han alcanzado la etapa de estudios clínicos debido a sus efectos inespecíficos, inestabilidad o baja permeabilidad celular. Los oligonucleótidos (ODNs) tipo señuelo son una alternativa para la terapia molecular dirigida. Estos han mostrado gran efectividad en diversos modelos de líneas celulares, junto con una mejor selectividad y mayor especificidad en sus efectos. Se seleccionó al factor de transcripción STAT3 como un blanco molecular potencial ya que su sobrexpresión en el tejido tumoral claramente se ha asociado con el desarrollo y progresión del cáncer de pulmón y a fenómenos de resistencia a medicamentos usados en clínica. El objetivo de este trabajo fue validar el potencial antitumoral de ODNs dirigidos contra STAT3 en líneas celulares de cáncer de pulmón teniendo en cuenta la selectividad y especificidad de los efectos. La expresión y activación de STAT3 fue medida por inmunofluorescencia para asegurar la presencia del blanco molecular en el modelo escogido. Posteriormente se cuantificó la captación celular de los ODNs por medio de citometría de flujo. Los efectos citotóxicos de los ODNs fueron determinados medio del ensayo metabólico de resazurina teniendo en cuenta diferentes concentraciones y tiempos de tratamientos. Finalmente se evaluó el posible mecanismo de muerte celular asociado a los tratamientos por medio de ensayos de actividad de caspasas y fragmentación nuclear por microscopía de fluorescencia. Los resultados mostraron que hubo una mayor expresión y activación del factor de transcripción STAT3 en las líneas tumorales respecto a una línea control de fibroblastos pulmonares. Además se encontró que los ODNs empleados fueron transfectados eficientemente en las células localizándose principalmente en el citoplasma. Mediante los ensayos de citotoxicidad se evidenció que los ODNs parental y modificado lograron la disminución de la supervivencia celular de forma dosis y tiempo dependiente alcanzando concentraciones letales 50 (CL50) en el rango nanomolar. Dichos efectos fueron exclusivos para las líneas tumorales y no para la línea celular normal demostrando la selectividad de los ODNs. Por otra parte se encontró que los ODNs bajo las condiciones de tratamiento indujeron un proceso de muerte por apoptosis y generaron cambios en la expresión de mRNA de tres genes blanco de STAT3. Estos resultados permitieron validar la tecnología de ODNs tipo señuelo como un modelo potencial de terapia dirigida con efectos selectivos sobre líneas celulares de cáncer de pulmón.Abstract. Currently, the cancer is still a disease with high mortality and incidence rates. The development of new molecules to treat the different cancer types is focused on targeted therapy. However, very few strategies have reached the stage of clinical trials due to their non-specific effects, instability or low cell uptake. Decoys oligonucleotides (ODNs) are an alternative for molecular targeted therapy and have shown high effectiveness in many cell lines with selectivity and specificity in their effects. We choose the STAT3 transcription factor as a potential molecular target since its overexpression in tumor tissue has been associated with development and progression of lung cancer and drug resistance in clinical practice. The aim of this research was to validate the antitumor potential of ODNs targeting STAT3 in lung cancer cell lines taking into consideration selective and specific effects. Protein expression and activation of STAT3 was measured by immunofluorescence to ensure the presence of the molecular target in the chosen model. Subsequently the cellular uptake of ODNs was quantified by flow cytometry. The cytotoxic effects of ODNs were determined using the resazurin metabolic assay, taking into account different concentrations and treatment times. Finally, the probable mechanism of cell death associated with the treatments was evaluated by caspase activity assays and nuclear fragmentation by fluorescence microscopy. The results showed a greater expression and activation of STAT3 in the tumor lines compared to a control line of pulmonary fibroblasts. In addition, it was found that the ODNs employed were efficiently transfected into cells and located mainly in the cytoplasm. Cytotoxicity assays revealed that the parental and modified ODNs achieved a decrease in cell survival in a dose and time dependent manner reaching lethal concentrations 50 (CL50) in the nanomolar range. These effects were exclusive for tumor cell lines and not for a normal cell line showing the selectivity of the ODNs. On the other hand, it was found that the ODNs under the conditions of treatment induced a death process by apoptosis and generated changes in the mRNA expression of three STAT3 target genes. These results validated the decoy ODNs as a potential model of targeted therapy with selective effects on lung cancer cell lines.Maestrí

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