Phosphate-activated cyclin-dependent kinase stabilizes G1 cyclin to trigger cell cycle entry

G1 cyclins, in association with a cyclin-dependent kinase (CDK), are universal activators of the transcriptional G1-S machinery during entry into the cell cycle. Regulation of cyclin degradation is crucial for coordinating progression through the cell cycle, but the mechanisms that modulate cyclin stability to control cell cycle entry are still unknown. Here, we show that a lack of phosphate downregulates Cln3 cyclin and leads to G1 arrest in Saccharomyces cerevisiae. The stability of Cln3 protein is diminished in strains with low activity of Pho85, a phosphate-sensing CDK. Cln3 is an in vitro substrate of Pho85, and both proteins interact in vivo. More interestingly, cells that carry a CLN3 allele encoding aspartic acid substitutions at the sites of Pho85 phosphorylation maintain high levels of Cln3 independently of Pho85 activity. Moreover, these cells do not properly arrest in G1 in the absence of phosphate and they die prematurely. Finally, the activity of Pho85 is essential for accumulating Cln3 and for reentering the cell cycle after phosphate refeeding. Taken together, our data indicate that Cln3 is a molecular target of the Pho85 kinase that is required to modulate cell cycle entry in response to environmental changes in nutrient availability. © 2013, American Society for Microbiology.S. Hernández received a postgraduate Junior Faculty fellowship from the UIC and l'Obra Social la Caixa. This work was supported by grants from Ministerio de Ciencia e Innovación of the Spanish government (BFU 2009-09278)Peer Reviewe

El juego como representación del signo en niños y niñas preescolares: un enfoque sociocultural

Desde la formulación sociocultural vigotskiana, los procesos psicológicos superiores tienen un origen social, es decir, que será la participación del sujeto en las actividades compartidas con los otros la condición y el modo en que se pueda dar cuenta de la operación de tales procesos. En este mismo sentido teórico, el juego es la actividad rectora mediante la cual el desarrollo del niño y la niña se ven comprometidos con la estructura de sus funciones mentales básicas y su movimiento a funciones mentales superiores. Para que este progreso ocurra, es necesario que a través del juego otro sujeto más capaz le facilite y le brinde los signos o instrumentos de mediación adecuados. Diversos autores de orientación vigotskiana han manifestado que dentro del aula es responsabilidad del grupo docente planear conscientemente estrategias lúdicas que le exijan al infante potenciar los signos necesarios que funcionen como apoyo y soporte para su desarrollo cognitivo. En correspondencia con lo anterior, el presente trabajo tiene como propósito describir el juego infantil como un medio para la representación de signos en una población de 45 niños y niñas de edad preescolar. Se adoptó el enfoque cualitativo a partir de la modalidad de estudio de caso interpretativo. Se efectuaron observaciones a los niños y las niñas dentro del aula, estas se registraron en un Diario de campo, de igual modo, se aplicaron entrevistas semiestructuradas a las docentes titulares y a la directora de la institución. Se trataron los resultados mediante el análisis de contenido. Por otro lado, aunque las profesoras entrevistadas definieron el juego infantil como un método de enseñanza para su práctica cotidiana, en la realidad los planes de trabajo pocos flexibles colocan a esta actividad en la periferia de su labor pedagógica. Se recomienda al personal docente reconocer el papel insoslayable del juego en la formación integral de menores del nivel preescolar y que este se vea reflejado en la incorporación de actividades lúdicas con objetivos claros y planes de trabajos flexibles que provoquen intencionadamente el uso de signos

Changes on cylindrospermopsin concentration and characterization of decomposition products in fish muscle (Oreochromis niloticus) by boiling and steaming

The occurrence of cylindrospermopsin (CYN) in toxic blooms of cyanobacteria is increasing in both frequency and distribution over the world. CYN persistence in water potentiates its accumulation in a wide range of aquatic animals destined to human consumption representing a serious problem. The aim of this work was to study for the first time the influence of cooking (boiling and steaming) for 1 or 2 min, on the stability of CYN in muscle of fish (Oreochromis niloticus) contaminated under laboratory conditions, also analyzing the waters in which samples were cooked. CYN was extracted and quantification was carried out by a developed and validated UPLC-MS/MS method. The results show that concentrations of CYN in fish are dependent on the cooking method, being the steaming for 2 min the most effective in reducing CYN levels (26%), followed by boiling for 2 min (18%), and significant differences have been found between the two periods assayed (1 min vs. 2 min). CYN was also detected in waters in which fish muscles were cooked in the range 0.10–0.28 μg/L. Moreover, characteristic decomposition products depending on the type of cooking were detected for the first time among the results of these treatments. The present findings emphasize the need for further studies to evaluate the influence of cooking in the presence of CYN in fish for a more realistic risk evaluation for the human health.Ministerio de Economía y Competitividad (AGL2015-64558-R, MINECO/FEDER, UE

Self-assembly of hexahistidine-tagged tobacco etch virus capsid protein into microfilaments that induce IgG2-specific response against a soluble porcine reproductive and respiratory syndrome virus chimeric protein

Antibody titers produced in sera of immunized mice recognizing His-TEV-CP protein. Immunization and ELISA procedures were conducted as described in Fig. 3 legend. Briefly explained, serum samples corresponding to bleeding 3 of mice group immunized with 25 μg of TEV VLPs (TEVVLPs25) were tested for total IgG and isotypes IgG1, IgG2a and IgG2b antibody response by ELISA in plates coated with with 1 μg of His-TEV-CP protein per well. Absorbance was taken at 450 nm in xMark spectrophotometer microplate reader (BioRad, USA). Results are expressed as antibody endpont titers greater than threefold the background value of preimmune sera. Excel was used for data processing. (TIFF 1142 kb

Competencias asociadas a la Atención a la diversidad y la inclusión: perspectiva del profesorado de Educación Infantil

Inclusive education should promote the existence of a variety of learning opportunities that facilitate the child's participation in activities with adults and peers and the necessary supports for all of this to occur. In this process, teachers have a strategic role in promoting practices that promote attention to diversity. Therefore, the skills they present at the didactic, organizational, communicative and integrative levels will be key to favor and not limit learning and participation in the classroom. Similarly, collaboration with early intervention services will be essential to support the student in a comprehensive manner. The study presented here has been carried out by knowing the perception of 68 teachers in Spain through the application of an ad hoc questionnaire. The results obtained highlight that the role of the teacher in nursery schools is fundamental, in addition to the development of various competencies that help to detect warning signs in the child, to intervene adequately with their students in a personalized way and to prioritize coordination with the CDIAT and its professionals, to offer more security and empowerment to the teacher in their educational work.La educación inclusiva debe promover la existencia de una variedad de oportunidades de aprendizaje que faciliten la participación del menor en actividades con los adultos y los compañeros y de los apoyos necesarios para que todo ello se produzca. En este proceso, los profesores tienen una función estratégica en la promoción de prácticas que promuevan la atención a la diversidad. Por tanto, las competencias que presenten a nivel didáctico, organizativo, comunicativo e integrativo serán clave para favorecer y no limitar el aprendizaje y la participación en el aula. Del mismo modo, la colaboración con los servicios de Atención Temprana será fundamental para apoyar al alumno de forma integral. El estudio que se presenta se ha llevado a cabo conociendo la percepción de 68 profesores de España a través de la aplicación de un cuestionario adhoc. En los resultados obtenidos destacan que el papel del docente en las escuelas infantiles es fundamental, además de que desarrolle variadas competencias que le ayuden a detectar signos de alarma en el menor, a intervenir adecuadamente a su alumnado de manera personalizada y siendo prioritaria la coordinación con el CDIAT y sus profesionales, para ofrecer más seguridad y empoderamiento al docente en su labor educativa

Mutagenic and genotoxic potential of pure Cylindrospermopsin by a battery of in vitro tests

Cylindrospermopsin (CYN) is a cyanobacterial toxin with an increasing world-wide occurrence. The main route of human exposure is through the ingestion of contaminated food and water. The European Food Safety Authority has identified the need to further characterize the toxicological profile of cyanotoxins and in this regard the genotoxicity is a key toxicological effect. The data available in the scientific literature show contradictory results. Thus, the aim of this study was to investigate the mutagenic and genotoxic effects of pure CYN using a battery of different in vitro assays including: the bacterial reverse-mutation assay in Salmonella typhimurium (Ames test) (0–10 μg/mL), the mammalian cell micronucleus (MN) test (0–1.35 μg/mL and 0–2 μg/mL in absence or presence of S9 fraction, respectively) and the mouse lymphoma thymidine-kinase assay (MLA)(0–0.675 μg/mL) on L5178YTk ± cells, and the standard and enzyme-modified comet assays (0–2.5 μg/mL) on Caco-2 cells. Positive results were obtained only when the metabolic fraction S9 was employed in the MN test, suggesting pro-genotoxic properties of CYN. Also, DNA damage was not mediated by oxidative stress as CYN did not induced changes in the modified comet assay. These data could contribute to a better risk assessment of this cyanotoxin.Ministerio de Economía y Competitividad (AGL2015-64558-R, MINECO/FEDER, U

In vitro toxicological assessment of an organosulfur compound from Allium extract: Cytotoxicity, mutagenicity and genotoxicity studies

Garlic (Allium sativum) and onion (Allium cepa) are being used in the food industry as flavoring but also for their antimicrobial activities. These activities are mainly derived from the organosulfur compounds (OSCs). Propyl propane thiosulfinate (PTS) is an OSC with potential use in the active packaging, but its safety should be guaranteed before being commercialized. The aim of this work was to investigate for the first time the cytotoxicity of PTS as well as its in vitro mutagenic/genotoxic potential using the following battery of genotoxicity tests:(1)the bacterial reverse-mutation assay in S. typhimurium (Ames test, OECD 471, 1997); (2) the micronucleus test (MN, OECD 487, 2016); (3) the mouse lymphoma thymidine-kinase assay (MLA, OECD 476, 2015), and (4) the comet assay (standard and modified with restriction enzymes). The results revealed that PTS was not mutagenic neither in the Ames test nor in MLA. However, genotoxic effects were recorded in the MN test on mammalian cells (L5178YTk+/−cells) after PTS exposure at the highest concentration tested (17.25 μM) without S9, and also its metabolites (+S9, from 20 μM). Moreover, in the comet assay, PTS induced DNA breaks damage in Caco-2 cells at the highest concentration tested (280 μM) but it did not induce oxidative DNA damage.Spanish Ministry of Scienceand Innovation (AGL2012-38357-C02-01) co-financed by FEDER fundsJunta de Andalucía (AGR-7252

A systematic analysis of orphan cyclins reveals CNTD2 as a new oncogenic driver in lung cancer

As lung cancer has increased to the most common cause of cancer death worldwide, prognostic biomarkers and effective targeted treatments remain lacking despite advances based on patients' stratification. Multiple core cyclins, best known as drivers of cell proliferation, are commonly deregulated in lung cancer where they may serve as oncogenes. The recent expansion of the cyclin family raises the question whether new members might play oncogenic roles as well. Here, we investigated the protein levels of eight atypical cyclins in lung cancer cell lines and formalin-fixed and paraffin-embedded (FFPE) human tumors, as well as their functional role in lung cancer cells. Of the new cyclins evaluated, CNTD2 was significantly overexpressed in lung cancer compared to adjacent normal tissue, and exhibited a predominant nuclear location. CNTD2 overexpression increased lung cancer cell viability, Ki-67 intensity and clonogenicity and promoted lung cancer cell migration. Accordingly, CNTD2 enhanced tumor growth in vivo on A549 xenograft models. Finally, the analysis of gene expression data revealed a high correlation between elevated levels of CNTD2 and decreased overall survival in lung cancer patients. Our results reveal CNTD2 as a new oncogenic driver in lung cancer, suggesting value as a prognostic biomarker and therapeutic target in this disease

The atypical cyclin CNTD2 promotes colon cancer cell proliferation and migration

Colorectal cancer (CRC) is one of the most common cancers worldwide, with 8-10% of these tumours presenting a BRAF (V600E) mutation. Cyclins are known oncogenes deregulated in many cancers, but the role of the new subfamily of atypical cyclins remains elusive. Here we have performed a systematic analysis of the protein expression levels of eight atypical cyclins in human CRC tumours and several cell lines, and found that CNTD2 is significantly upregulated in CRC tissue compared to the adjacent normal one. CNTD2 overexpression in CRC cell lines increases their proliferation capacity and migration, as well as spheroid formation capacity and anchorage-independent growth. Moreover, CNTD2 increases tumour growth in vivo on xenograft models of CRC with wild-type BRAF. Accordingly, CNTD2 downregulation significantly diminished the proliferation of wild-type BRAF CRC cells, suggesting that CNTD2 may represent a new prognostic factor and a promising drug target in the management of CRC

The overlooked immune state in candidemia: A risk factor for mortality

Producción CientíficaLymphopenia has been related to increased mortality in septic patients. Nonetheless, the impact of lymphocyte count on candidemia mortality and prognosis has not been addressed. We conducted a retrospective study, including all admitted patients with candidemia from 2007 to 2016. We examined lymphocyte counts during the first 5 days following the diagnosis of candidemia. Multivariable logistic regression analysis was performed to determine the relationship between lymphocyte count and mortality. Classification and Regression Tree analysis was used to identify the best cut-off of lymphocyte count for mortality associated with candidemia. From 296 cases of candidemia, 115 died, (39.8% 30-day mortality). Low lymphocyte count was related to mortality and poor outcome (p < 0.001). Lymphocyte counts <0.703 × 109 cells/L at diagnosis (area under the curve (AUC)-ROC, 0.783 ± 0.042; 95% confidence interval (CI), 0.700–0.867, p < 0.001), and lymphocyte count <1.272 × 109 cells/L five days later (AUC-ROC, 0.791 ± 0.038; 95%CI, 0.716–0.866, p < 0.001) increased the odds of mortality five-fold (odds ratio (OR), 5.01; 95%CI, 2.39–10.93) at time of diagnosis, and three-fold (OR, 3.27; 95%CI, 1.24–8.62) by day 5, respectively. Low lymphocyte count is an independent predictor of mortality in patients with candidemia and might serve as a biomarker for predicting candidemia-associated mortality and poor outcome.Junta de Castilla y León (grant VA161G18