Nuevas formulaciones para el tratamiento de la leishmaniosis

La leishmaniosis engloba un complejo de enfermedades originadas por parásitos protozoos intracelulares del género Leishmania, cuya transmisión se lleva a cabo mediante la picadura de las hembras infectadas de los géneros Phlebotomus y Lutzomyia, más comúnmente conocida como mosca de la arena. Esta enfermedad constituye una zoonosis endémica a lo largo de mundo, y a día de hoy continúa siendo un grave problema de salud ciertamente olvidado, ya que los recursos destinados tanto a su investigación como al tratamiento son bastantes pobres. Se pueden diferenciar cuatro formas principales de leishmaniosis: visceral, cutánea, mucocutánea y cutánea difusa. La presencia tanto de distintas especies de Leishmania como de las diversas manifestaciones clínicas que pueden tener lugar conlleva una complicación de la terapéutica. Aunque se disponen de varios medicamentos antileishmania en el mercado, estos presentan serias limitaciones como son su alto nivel de toxicidad y su baja efectividad, así como la aparición de resistencias parasitarias. Frente a este problema, se están desarrollando nuevas formulaciones basadas en nanosistemas cuyos resultados sugieren ser una vía prometedora para la mejora del tratamiento frente a la leishmaniosis en un futuro. En el presente trabajo se llevará a cabo una revisión mediante la que se intentará abordar las nuevas formulaciones existentes o en vía de desarrollo, junto con sus posibilidades para el tratamiento contra la leishmaniosis; así como la intención de reportar las dificultades y deficiencias ante las que nos encontramos respecto a la lucha frente a dicha enfermedad

Suv4-20h Abrogation Enhances Telomere Elongation during Reprogramming and Confers a Higher Tumorigenic Potential to iPS Cells

Reprogramming of adult differentiated cells to induced pluripotent stem cells (iPS) cells has been achieved by over-expression of specific transcription factors. Nuclear reprogramming induces a series of profound changes at the telomeres of the parental differentiated cells, including a telomerase-dependent telomere elongation and the remodeling of telomeric chromatin. In particular, iPS cells show a decreased density of H4K20me3 heterochromatic mark at telomeres compared to the parental cells. Suv4-20h1 and Suv4-20h2 histone methytransferases (HMTases) are responsible for the trimethylation of H4K20 at telomeres, as cells deficient for both HMTases show decreased levels of H4K20me3 at telomeric chromatin. Here, we set to address the role of the Suv4-20h enzymes in telomere reprogramming by generating bona-fide iPS cells from mouse embryonic fibroblasts (MEFs) double null for both HMTases (Suv4-20dn MEFs). We found that Suv4-20h deficiency enhances telomere elongation during reprogramming without altering their ability to protect the chromosome ends or the efficiency of reprogramming. Moreover, teratomas generated from Suv4-20dn iPS cells also have elongated telomeres and an increased growth rate when compared to wild-type controls. These results indicate that abrogation of Suv4-20h enzymes and loss of heterochromatic mark H4K20me3 at telomeric heterochromatin facilitates telomere reprogramming and provides an increased tumorigenic potential to the resulting iPS cells

Generation of mice with longer and better preserved telomeres in the absence of genetic manipulations

Although telomere length is genetically determined, mouse embryonic stem (ES) cells with telomeres of twice the normal size have been generated. Here, we use such ES cells with 'hyper-long' telomeres, which also express green fluorescent protein (GFP), to generate chimaeric mice containing cells with both hyper-long and normal telomeres. We show that chimaeric mice contain GFP-positive cells in all mouse tissues, display normal tissue histology and normal survival. Both hyper-long and normal telomeres shorten with age, but GFP-positive cells retain longer telomeres as mice age. Chimaeric mice with hyper-long telomeres also accumulate fewer cells with short telomeres and less DNA damage with age, and express lower levels of p53. In highly renewing compartments, such as the blood, cells with hyper-long telomeres are longitudinally maintained or enriched with age. We further show that wound-healing rates in the skin are increased in chimaeric mice. Our work demonstrates that mice with functional, longer and better preserved telomeres can be generated without the need for genetic manipulations, such as TERT overexpression.M. A. Blasco’s laboratory is funded by the Spanish Ministry of Economy and Competitiveness Project SAF2013-45111RETOS, the European Union FP7 Project EUROBATS, the European Research Council (ERC) Project TEL STEM CELL (GA#232854), the Regional Government of Madrid 2þ2 ReCaRe, the AXA Research Fund and the Fundacion BotınS

Generation of mice with longer and better preserved telomeres in the absence of genetic manipulations.

Although telomere length is genetically determined, mouse embryonic stem (ES) cells with telomeres of twice the normal size have been generated. Here, we use such ES cells with ‘hyper-long’ telomeres, which also express green fluorescent protein (GFP), to generate chimaeric mice containing cells with both hyper-long and normal telomeres. We show that chimaeric mice contain GFP-positive cells in all mouse tissues, display normal tissue histology and normal survival. Both hyper-long and normal telomeres shorten with age, but GFP-positive cells retain longer telomeres as mice age. Chimaeric mice with hyper-long telomeres also accumulate fewer cells with short telomeres and less DNA damage with age, and express lower levels of p53. In highly renewing compartments, such as the blood, cells with hyper-long telomeres are longitudinally maintained or enriched with age. We further show that wound-healing rates in the skin are increased in chimaeric mice. Our work demonstrates that mice with functional, longer and better preserved telomeres can be generated without the need for genetic manipulations, such as TERT overexpression.post-print3240 K

Endogenous retroviruses shape pluripotency specification in mouse embryos.

The smooth and precise transition from totipotency to pluripotency is a key process in embryonic development, generating pluripotent stem cells capable of forming all cell types. While endogenous retroviruses (ERVs) are essential for early development, their precise roles in this transition remains mysterious. Using cutting-edge genetic and biochemical techniques in mice, we identify MERVL-gag, a retroviral protein, as a crucial modulator of pluripotent factors OCT4 and SOX2 during lineage specification. MERVL-gag tightly operates with URI, a prefoldin protein that concurs with pluripotency bias in mouse blastomeres, and which is indeed required for totipotency-to-pluripotency transition. Accordingly, URI loss promotes a stable totipotent-like state and embryo arrest at 2C stage. Mechanistically, URI binds and shields OCT4 and SOX2 from proteasome degradation, while MERVL-gag displaces URI from pluripotent factor interaction, causing their degradation. Our findings reveal the symbiotic coevolution of ERVs with their host cells to ensure the smooth and timely progression of early embryo development.acknowledgments: We thank all mouse providers as described in Materials and Methods. We also thank the cniO Animal Facility for mouse maintenance. We acknowledge M. Ko (Keio University, Systems Medicine, Japan) for providing the pZscan4- emerald reporter plasmid. Funding: S.d.l.R. was supported by a fellowship from the comunidad de Madrid and by funds from the Severo Ochoa- cniO. this work was funded by grants to n.d. supported by the State Research Agency (Aei; 10.13039/501100011033) from the Spanish Ministry of Science and innovation (Rti2018- 094834- B- i00 and Pid2021- 122695OB- i00), also including the idiFFeR network of excellence (Red2022- 134792- t), cofunded by european Regional development Fund (eRdF), by the comunidad Autónoma de Madrid (S2017/BMd- 3817), and by the Asociación española contra el cáncer (Aecc) (PRYGn211184dJOU). this work was developed at the cniO funded by the health institute carlos iii (iSciii) and the Spanish Ministry of Science and innovation. Author contributions: S.d.l.R. designed and performed the experiments and analyzed all the data. S.d.l.R. analyzed all the bioinformatics data. M.d.M.R. performed some experiments. P.v. and S.O. performed microinjection in vivo and chimera embryo assay. S.d.l.R and n.d. developed the project and wrote the manuscript. n.d. conceived the project and secured funding. Competing interests:the authors declare that they have no competing interests. Data and materials availability: All data are available in the main text or Materials and Methods. Materials are available upon request to n.d. and the sharing of materials described in this work will be subject to standard material transfer agreementsS

A Genome-wide CRISPR Screen Identifies CDC25A as a Determinant of Sensitivity to ATR Inhibitors

One recurring theme in drug development is to exploit synthetic lethal properties as means to preferentially damage the DNA of cancer cells. We and others have previously developed inhibitors of the ATR kinase, shown to be particularly genotoxic for cells expressing certain oncogenes. In contrast, the mechanisms of resistance to ATR inhibitors remain unexplored. We report here on a genome-wide CRISPR-Cas9 screen that identified CDC25A as a major determinant of sensitivity to ATR inhibition. CDC25A-deficient cells resist high doses of ATR inhibitors, which we show is due to their failure to prematurely enter mitosis in response to the drugs. Forcing mitotic entry with WEE1 inhibitors restores the toxicity of ATR inhibitors in CDC25A-deficient cells. With ATR inhibitors now entering the clinic, our work provides a better understanding of the mechanisms by which these compounds kill cells and reveals genetic interactions that could be used for their rational use.We thank the laboratories of Feng Zhang and Kosuke Yusa for sharing all CRISPR-related plasmids used here through Addgene (plasmids 42230, 50946, and 50947) and Edna Fonseca for her comments on the manuscript. Research was funded by Fundacion Botin, Banco Santander, through its Santander Universities Global Division and by grants from the Spanish Ministry of Economy and Competitiveness (MINECO) (SAF2011-23753 and SAF2014-57791-REDC), Fundacio La Marato de TV3, the Howard Hughes Medical Institute, and the European Research Council (ERC-617840) to O.F.-C.; by a PhD fellowship from La Caixa Foundation to C.M.-R.; by grants from MINECO to S.R. (RYC2011-09242 and SAF2013-49147P, this last project co-financed with European FEDER funds); and by a grant from MINECO (SAF2013-44866-R) to S.O.S

Detección de cambios en las concepciones sobre el huerto de alumnado de secundaria en base a representaciones gráficas

Se presenta un estudio sobre alumnos/as de 3º de la ESO, realizado en el marco Proyecto de Investigación EDUJCYL2016-INV03-Cultivate a better world, de la Consejería de Educación de la Junta de Castilla y León, parte de los cuales (n=49) participaron en el curso 2015/2016, y en el marco de la asignatura Ciencias Naturales, en el proyecto Los bancales del Espino, de acondicionamiento de un huerto educativo en el centro; el resto (n=22) no lo hicieron. A principios del curso 2016/2017 se les solicitó que llevaran a cabo la representación gráfica de un huerto. Estas representaciones fueron analizadas por un equipo que incluye a la profesora de Educación Artística, desde dos enfoques: uno cualitativo, mediante el que se clasifican en grupos en base a criterio de experto, y otro cuantitativo, mediante el que se obtienen frecuencias de aparición de elementos. Se presentan los resultados y se reflexiona sobre el valor de la metodología utilizada y las consecuencias de la experiencia para la mejora de la práctica docente

A Chemical Screen Identifies Compounds Capable of Selecting for Haploidy in Mammalian Cells

The recent availability of somatic haploid cell lines has provided a unique tool for genetic studies in mammals. However, the percentage of haploid cells rapidly decreases in these cell lines, which we recently showed is due to their overgrowth by diploid cells present in the cultures. Based on this property, we have now performed a phenotypic chemical screen in human haploid HAP1 cells aiming to identify compounds that facilitate the maintenance of haploid cells. Our top hit was 10-Deacetyl-baccatin-III (DAB), a chemical precursor in the synthesis of Taxol, which selects for haploid cells in HAP1 and mouse haploid embryonic stem cultures. Interestingly, DAB also enriches for diploid cells in mixed cultures of diploid and tetraploid cells, including in the colon cancer cell line DLD-1, revealing a general strategy for selecting cells with lower ploidy in mixed populations of mammalian cells.We would like to thank the members of the O.F.-C. laboratory and MonicaAlvarez-Fernandez for insightful comments and the Transgenic Mice, FlowCytometry, and Confocal Microscopy Units from the CNIO for their technicalhelp. T.O. was funded by a PhD fellowship from Boehringer IngelheimFonds. Research was funded by Fundacion Botı n, Banco Santander throughits Santander Universities Global Division, and by grants from MINECO(SAF2014-57791-REDC and SAF2014-59498-R to O.F.-C., SAF-2013-44866-R to S.O., and SAF2013-49147-P and SAF2016-80874-P to S.R.; pro-jects that were co-financed with ERDF-EU funds) and the EuropeanResearch Council (ERC-617840). Research at the G.d.C. laboratory is fundedby the AECC Scientific Foundation (LABAE16017DECA).S

Lockdown, Emotional Intelligence, Academic Engagement and Burnout in Pharmacy Students during the Quarantine

The recent appearance and rapid spread of the new SARS-CoV-2 coronavirus meant taking unprecedented measures to control the pandemic, which in Spain forced a state of alarm and a very strict confinement, leading the university system to become virtual online teaching. Taking into account the emotional deficiencies originated during the pandemic, among the most powerful tools to achieve engagement along with the identification, control and management of emotions is emotional intelligence (EI). The present study aims to establish the effect of the current confinement on the teaching-learning process and academic performance and the impact of the application of EI on university students. In total, 47 volunteers of the second course of the Degree in Pharmacy of the University of Granada (Spain) took part in this experience. Two temporary periods were established: at the beginning of the confinement period and after teaching several concepts of emotional intelligence online for two months. The Maslach Burnout Inventory-Student Survey Inventory (MBI-SS) and the Spanish version of Utrech Work Engagement Scale-Students (UWES-S) were used to evaluate the intervention. In total, 63.5% of the students presented academic burnout during the confinement before the intervention. After the EI workshops and seminars, only 31.1% presented academic burnout. Before the intervention with the emotional intelligence workshops, 44.6% experienced exhaustion, 41.7% cynicism and 60.3% felt it was ineffective in their academic performance. After the emotional intelligence workshops and seminars, 29.1% experienced exhaustion, 30.1% cynicism and 28.8% felt it was ineffective. The scores achieved after the study of EI in physiology classes led to better levels in all the variables studied. Students managed their adaptive processes more adequately and regulated their emotions better, as they felt less academic burnout and more engaged in their academic activities at the end of the study of EI through physiolog