Crosstalk between chromatin structure, cohesin activity and transcription

Background: A complex interplay between chromatin and topological machineries is critical for genome architec‑ ture and function. However, little is known about these reciprocal interactions, even for cohesin, despite its multiple roles in DNA metabolism. Results: We have used genome‑wide analyses to address how cohesins and chromatin structure impact each other in yeast. Cohesin inactivation in scc1‑73 mutants during the S and G2 phases causes specific changes in chromatin structure that preferentially take place at promoters; these changes include a significant increase in the occupancy of the − 1 and + 1 nucleosomes. In addition, cohesins play a major role in transcription regulation that is associated with specific promoter chromatin architecture. In scc1‑73 cells, downregulated genes are enriched in promoters with short or no nucleosome‑free region (NFR) and a fragile “nucleosome − 1/RSC complex” particle. These results, together with a preferential increase in the occupancy of nucleosome − 1 of these genes, suggest that cohesins promote transcription activation by helping RSC to form the NFR. In sharp contrast, the scc1‑73 upregulated genes are enriched in promoters with an “open” chromatin structure and are mostly at cohesin‑enriched regions, suggesting that a local accumulation of cohesins might help to inhibit transcription. On the other hand, a dramatic loss of chromatin integrity by histone depletion during DNA replication has a moderate effect on the accumulation and distribution of cohesin peaks along the genome. Conclusions: Our analyses of the interplay between chromatin integrity and cohesin activity suggest that cohesins play a major role in transcription regulation, which is associated with specific chromatin architecture and cohesin‑ mediated nucleosome alterations of the regulated promoters. In contrast, chromatin integrity plays only a minor role in the binding and distribution of cohesins.Spanish Ministry of Economy and Competitivenes BFU2012-38171, BFU2015-63698-PAndalusian Government P12-CTS-227

Loss of glutathione redox homeostasis impairs proteostasis by inhibiting autophagy-dependent protein degradation

In the presence of aggregation-prone proteins, the cytosol and endoplasmic reticulum (ER) undergo a dramatic shift in their respective redox status, with the cytosol becoming more oxidized and the ER more reducing. However, whether and how changes in the cellular redox status may affect protein aggregation is unknown. Here, we show that C. elegans loss-of-function mutants for the glutathione reductase gsr-1 gene enhance the deleterious phenotypes of heterologous human, as well as endogenous worm aggregation-prone proteins. These effects are phenocopied by the GSH-depleting agent diethyl maleate. Additionally, gsr-1 mutants abolish the nuclear translocation of HLH-30/TFEB transcription factor, a key inducer of autophagy, and strongly impair the degradation of the autophagy substrate p62/SQST-1::GFP, revealing glutathione reductase may have a role in the clearance of protein aggregates by autophagy. Blocking autophagy in gsr-1 worms expressing aggregation-prone proteins results in strong synthetic developmental phenotypes and lethality, supporting the physiological importance of glutathione reductase in the regulation of misfolded protein clearance. Furthermore, impairing redox homeostasis in both yeast and mammalian cells induces toxicity phenotypes associated with protein aggregation. Together, our data reveal that glutathione redox homeostasis may be central to proteostasis maintenance through autophagy regulation.. The Spanish Ministry of Economy and Competitiveness supported EF-S and VG (BFU2016–78265-P), PA (BFU2016– 79313-P and MDM-2016–0687), and AM-V (BFU2015–64408-P). AM-V was also supported by the Instituto de Salud Carlos III (PI11/ 00072) and RPV-M (CPII16/00004, PI14/00949 and PI17/00011). All projects were cofinanced by the Fondo Social Europeo (FEDER). AM-V is a member of the GENIE and EU-ROS Cost Actions of the European Union and RPV-M is a Marie Curie Fellow (CIG322034, EU)

Loss of glutathione redox homeostasis impairs proteostasis by inhibiting autophagy-dependent protein degradation

Trabajo presentado en el VII Spanish Worm Meeting (SWN), celebrado en Castelldefels (Barcelona) el 28 y 29 de marzo de 2019.Peer reviewe

A primary healthcare information intervention for communicating cardiovascular risk to patients with poorly controlled hypertension: The Education and Coronary Risk Evaluation (Educore) study-A pragmatic, cluster-randomized trial

PURPOSE: Uncertainty exists regarding the best way to communicate cardiovascular risk (CVR) to patients, and it is unclear whether the comprehension and perception of CVR varies according to the format used. The aim of the present work was to determine whether a strategy designed for communicating CVR information to patients with poorly controlled high blood pressure (HBP), but with no background of cardiovascular disease, was more effective than usual care in the control of blood pressure (BP) over the course of a year. METHODS: A pragmatic, two-arm, cluster-randomized controlled trial was performed. Consecutive patients aged 40-65 years, all diagnosed with HBP in the last 12 months, and all of whom showed poor control of their condition (systolic BP ≥140 mmHg and/or diastolic BP ≥90 mmHg), were recruited at 22 primary healthcare centres. Eleven centres were randomly assigned to the usual care arm, and 11 to the informative intervention arm (Educore arm). At the start of the study, the Educore arm subjects were shown the "low risk SCORE table", along with impacting images and information pamphlets encouraging the maintenance of good cardiovascular health. The main outcome variable measured was the control of HBP; the secondary outcome variables were SCORE table score, total plasma cholesterol concentration, use of tobacco, adherence to prescribed treatment, and quality of life. RESULTS: The study participants were 411 patients (185 in the Educore arm and 226 in the usual care arm). Multilevel logistic regression showed that, at 12 months, the Educore intervention achieved better control of HBP (OR = 1.57; 1.02 to 2.41). No statistically significant differences were seen between the two arms at 12 months with respect to the secondary outcomes. CONCLUSIONS: Compared to usual care, the Educore intervention was associated with better control of HBP after adjusting for age, baseline SBP and plasma cholesterol, at 12 months.This study was funded by the Spanish Ministry of Science and Innovation via the Instituto de Salud Carlos III, Subprograma de Proyectos de Investigación en Evaluación de Tecnologías Sanitarias y Servicios de Salud (PI 09/90354), and the Fundación de Investigación e Innovación Biomédica en Atención Primaria (FIIBAP). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscriptS

Defective histone supply causes condensin-dependent chromatin alterations, SAC activation and chromosome decatenation impairment

The structural organization of chromosomes is essential for their correct function and dynamics during the cell cycle. The assembly of DNA into chromatin provides the substrate for topoisomerases and condensins, which introduce the different levels of superhelical torsion required for DNA metabolism. In particular, Top2 and condensin are directly involved in both the resolution of precatenanes that form during replication and the formation of the intramolecular loop that detects tension at the centromeric chromatin during chromosome biorientation. Here we show that histone depletion activates the spindle assembly checkpoint (SAC) and impairs sister chromatid decatenation, leading to chromosome mis-segregation and lethality in the absence of the SAC. We demonstrate that histone depletion impairs chromosome biorientation and activates the Aurora-dependent pathway, which detects tension problems at the kinetochore. Interestingly, SAC activation is suppressed by the absence of Top2 and Smc2, an essential component of condensin. Indeed, smc2-8 suppresses catenanes accumulation, mitotic arrest and growth defects induced by histone depletion at semi-permissive temperature. Remarkably, SAC activation by histone depletion is associated with condensin-mediated alterations of the centromeric chromatin. Therefore, our results reveal the importance of a precise interplay between histone supply and condensin/Top2 for pericentric chromatin structure, precatenanes resolution and centromere biorientation.Ministerio de Ciencia BFU2009-09036 BFU2012- 3817

Defective histone supply causes condensin-dependent chromatin alterations, SAC activation and chromosome decatenation impairment

The structural organization of chromosomes is essential for their correct function and dynamics during the cell cycle. The assembly of DNA into chromatin provides the substrate for topoisomerases and condensins, which introduce the different levels of superhelical torsion required for DNA metabolism. In particular, Top2 and condensin are directly involved in both the resolution of precatenanes that form during replication and the formation of the intramolecular loop that detects tension at the centromeric chromatin during chromosome biorientation. Here we show that histone depletion activates the spindle assembly checkpoint (SAC) and impairs sister chromatid decatenation, leading to chromosome mis-segregation and lethality in the absence of the SAC. We demonstrate that histone depletion impairs chromosome biorientation and activates the Aurora-dependent pathway, which detects tension problems at the kinetochore. Interestingly, SAC activation is suppressed by the absence of Top2 and Smc2, an essential component of condensin. Indeed, smc2-8 suppresses catenanes accumulation, mitotic arrest and growth defects induced by histone depletion at semi-permissive temperature. Remarkably, SAC activation by histone depletion is associated with condensin-mediated alterations of the centromeric chromatin. Therefore, our results reveal the importance of a precise interplay between histone supply and condensin/Top2 for pericentric chromatin structure, precatenanes resolution and centromere biorientation.Ministerio de Ciencia BFU2009-09036 BFU2012- 3817

Validation of a Set of Instruments to Assess Patient- and Caregiver-Oriented Measurements in Spinal Muscular Atrophy: Results of the SMA-TOOL Study.

Outcome measures traditionally used in spinal muscular atrophy (SMA) clinical trials are inadequate to assess the full range of disease severity. The aim of this study was to assess the psychometric properties of a set of existing questionnaires and new items, gathering information on the impact of SMA from the patient and caregiver perspectives. This was a multicenter, prospective, noninterventional study including patients with a confirmed diagnosis of 5q-autosomal-recessive SMA aged 8 years and above, or their parents (if aged between 2 and 8 years). The set of outcome measurements included the SMA Independence Scale (SMAIS) patient and caregiver versions, the Neuro-QoL Fatigue Computer Adaptive Test (CAT), the Neuro-QoL Pain Short Form-Pediatric Pain, the PROMIS adult Pain Interference CAT, and new items developed by Fundación Atrofia Muscular España: perceived fatigability, breathing and voice, sleep and rest, and vulnerability. Reliability, construct validity, discriminant validity, and sensitivity to change (4 months from baseline) were measured. A total of 113 patients were included (59.3% 2-17 years old, 59.3% male, and 50.4% with SMA type II). Patients required moderate assistance [mean patient and caregiver SMAIS (SD) scores were 31.1 (12.8) and 7.6 (11.1), respectively]. Perceived fatigability was the most impacted domain, followed by vulnerability. Cronbach's alpha coefficient for perceived fatigability, breathing and voice, and vulnerability total scores were 0.92, 0.88, and 0.85, respectively. The exploratory factor analysis identified the main factors considered in the design, except in the sleep and rest domain. All questionnaires were able to discriminate between the Clinical Global Impression-Severity scores and SMA types. Sensitivity to change was only found for the SMAIS caregiver version and vulnerability items. This set of outcome measures showed adequate reliability, construct validity, and discriminant validity and may constitute a valuable option to measure symptom severity in patients with SMA

Leocadia : una mascota transgénero

El trabajo obtuvo una mención honorífica del Premio Tomás García Verdejo a las buenas prácticas educativa en la Comunidad Autónoma de Extremadura para el curso 2020/2021. Modalidad ASe describe un proyecto llevado a cabo desde la biblioteca del CEIP Extremadura (Cáceres) que pretendía modernizar la imagen que se tenía del centro. Se realizaron dos bloques de actividades. En el primer bloque se creó la imagen y leyenda de la biblioteca, 'Leocadia' una mascota transgénero que buscaba su identidad a través de los libros, enseñando valores esenciales para el crecimiento de los alumnos. En el segundo bloque se desarrollaron proyectos articulados desde la biblioteca: 'Y llegaron las científicas' sobre el papel de la mujer en la Ciencia; 'Radio Ciconia' la radio escolar del centro; 'Mi cole con mucho arte' en el que a través de la pintura-escultura y la música se pusieron de manifiesto los valores de respeto, igualdad, etc.ExtremaduraES