Characterizatión of the DIDO3-SFPQ axis in alternative splicing

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 26-04-2019Alternative splicing is a fundamental mechanism that allows the generation of multiple isoforms of the same pre-mRNA. Although splicing is a necessary process in all eukaryotes from yeast to mammals, alternative splicing is more prevalent in higher than lower eukaryotes, and especially in vertebrates. Nearly 95% of mammalian genes undergo alternative splicing, so mis-regulation of this process may contribute to the development of different diseases such as cancer. This higher level of regulation requires additional proteins to facilitate the correct positioning of the spliceosomal subunits on the primary transcript. Here, we reveal a role for DIDO3, one of the three Dido gene products, in SFPQ binding and alternative splicing. Previous studies in our laboratory established binding to H3K4Me3 through a PHD domain located at the amino terminal region of the protein. A TFS2M domain at the central part of DIDO3 promotes association with the RNAPII jaw during transcription elongation. Now, we show interaction between the carboxy-terminus of DIDO3 and SFPQ, a known splicing factor. SFPQ is a protein that associates with the polypyrimidine tract, and in particular facilitates correct U2 snRNP positioning on the 3’ splice site of exons. The generation of a Dido mutant lacking DIDO3 while preserving the other two isoforms suppressed binding of SFPQ to RNA and increased skipping for a large general group of exons. Exons containing SRSF1 recognition sequences however were included more efficiently. Alternative splicing was also studied in the context of another Dido mutant. The deletion of the amino terminal region of DIDO3, too, resulted in alternatively spliced exons, although the observed splicing defects were milder. In this mutant, downstream T-rich regions, associated with RNA polymerase II pause sites, facilitated the inclusion of their upstream exons. Together, our results indicate that the DIDO3-SFPQ association regulates alternative splicing. Due to its modular structure, DIDO3 could act as a bridge between RNA polymerase II and SFPQ, and thereby control the recruitment of the latter to the nascent RNA. Lack of the DIDO3-specific domain reduces SFPQ availability for the RNA and promotes the skipping of exons that are highly SFPQ-dependent. Although alternative pathways also regulate exon inclusion or skipping, we propose that the DIDO3-SFPQ axis in particular has evolved to expand alternative splicing regulation and maintain RNA splicing efficiency in mammals

Chromatin condensation and recruitment of PHD finger proteins to histone H3K4me3 are mutually exclusive

Histone post-translational modifications, and specific combinations they create, mediate a wide range of nuclear events. However, the mechanistic bases for recognition of these combinations have not been elucidated. Here, we characterize crosstalk between H3T3 and H3T6 phosphorylation, occurring in mitosis, and H3K4me3, a mark associated with active transcription. We detail the molecular mechanisms by which H3T3ph/K4me3/T6ph switches mediate activities of H3K4me3-binding proteins, including those containing plant homeodomain (PHD) and double Tudor reader domains. Our results derived from nuclear magnetic resonance chemical shift perturbation analysis, orthogonal binding assays and cell fluorescence microscopy studies reveal a strong anti-correlation between histone H3T3/T6 phosphorylation and retention of PHD finger proteins in chromatin during mitosis. Together, our findings uncover the mechanistic rules of chromatin engagement for H3K4me3-specific readers during cell division

Cardiac dysfunction and remodeling regulated by anti-angiogenic environment in patients with preeclampsia : the ANGIOCOR prospective cohort study protocol

Background: Cardiovascular diseases (CVD) are cause of increased morbidity and mortality in spite of advances for diagnosis and treatment. Changes during pregnancy affect importantly the maternal CV system. Pregnant women that develop preeclampsia (PE) have higher risk (up to 4 times) of clinical CVD in the short- and long-term. Predominance of an anti-angiogenic environment during pregnancy is known as main cause of PE, but its relationship with CV complications is still under research. We hypothesize that angiogenic factors are associated to maternal cardiac dysfunction/remodeling and that these may be detected by new cardiac biomarkers and maternal echocardiography. Methods: Prospective cohort study of pregnant women with high-risk of PE in first trimester screening, established diagnosis of PE during gestation, and healthy pregnant women (total intended sample size n = 440). Placental biochemical and biophysical cardiovascular markers will be assessed in the first and third trimesters of pregnancy, along with maternal echocardiographic parameters. Fetal cardiac function at third trimester of pregnancy will be also evaluated and correlated with maternal variables. Maternal cardiac function assessment will be determined 12 months after delivery, and correlation with CV and PE risk variables obtained during pregnancy will be evaluated. Discussion: The study will contribute to characterize the relationship between anti-angiogenic environment and maternal CV dysfunction/remodeling, during and after pregnancy, as well as its impact on future CVD risk in patients with PE. The ultimate goal is to improve CV health of women with high-risk or previous PE, and thus, reduce the burden of the disease. Trial registration: NCT04162236

EVALUATION OF THE CHELATING EFFECT OF METHANOLIC EXTRACT OF CORIANDRUM SATIVUM AND ITS FRACTIONS ON WISTAR RATS POISONED WITH LEAD ACETATE

Background: The rate of lead poisoning has decreased in recent years due to increased health control in industries that use this metal. However, it is still a public health problem worldwide. The use of various plants with chelating properties has been a topic of research today. In traditional medicine, it is said that Coriandrum sativum has chelating properties, but there is no scientific evidence to support this fact. The purpose of this research is to evaluate the chelating effect of methanol extract of coriander and its fractions on Wistar rats intoxicated with lead. Materials and Methods: In this research, male Wistar rats were poisoned with 50 mg/kg of lead acetate and treated with 50 mg/kg of methanol extract and its fractions. The extract and its fractions were administered to four treatment groups. Positive and negative controls were established. Hemoglobin, hematocrit and lead concentrations were analyzed; liver was evaluated histologically in control and treatment groups. Results: The methanol extract of coriander presented a LD50 ˃1000 mg/dL. The group administered with the methanol extract showed significant difference in the levels of hemoglobin and hematocrit compared to the negative control group. Lead concentration in treatment groups showed a decrease compared to the positive control. Histological evaluation of tissue showed less damage in groups administered with methanolic extract and its fractions compared to the positive control which presented structural alterations. Conclusion: Coriander extracts protect liver and lower lead concentration in rats intoxicated with lead in contrast to the positive control group

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

CIBERER : Spanish national network for research on rare diseases: A highly productive collaborative initiative

Altres ajuts: Instituto de Salud Carlos III (ISCIII); Ministerio de Ciencia e Innovación.CIBER (Center for Biomedical Network Research; Centro de Investigación Biomédica En Red) is a public national consortium created in 2006 under the umbrella of the Spanish National Institute of Health Carlos III (ISCIII). This innovative research structure comprises 11 different specific areas dedicated to the main public health priorities in the National Health System. CIBERER, the thematic area of CIBER focused on rare diseases (RDs) currently consists of 75 research groups belonging to universities, research centers, and hospitals of the entire country. CIBERER's mission is to be a center prioritizing and favoring collaboration and cooperation between biomedical and clinical research groups, with special emphasis on the aspects of genetic, molecular, biochemical, and cellular research of RDs. This research is the basis for providing new tools for the diagnosis and therapy of low-prevalence diseases, in line with the International Rare Diseases Research Consortium (IRDiRC) objectives, thus favoring translational research between the scientific environment of the laboratory and the clinical setting of health centers. In this article, we intend to review CIBERER's 15-year journey and summarize the main results obtained in terms of internationalization, scientific production, contributions toward the discovery of new therapies and novel genes associated to diseases, cooperation with patients' associations and many other topics related to RD research

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M&gt;70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0&lt;e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

Sintaxis y prosodia: el análisis sintáctico de las unidades del discurso oral

En este trabajo se propone el análisis sintáctico de los segmentos delimitados prosódicamente en una muestra de datos de habla oral cuyo análisis acústico presentamos en Mora, Martínez y Domínguez (2009). El análisis sintáctico que aquí nos ocupa nos permite concluir que las unidades de entonación tienden a delimitar una unidad de información que se realiza preferentemente como una oración (independiente o no), aunque tenemos también en nuestros datos una frecuencia relativamente alta de sintagmas delimitados entonativamente que no siempre pueden relacionarse por su función con la oración en el contexto (lo que no significa que no cumplan una función en el contexto más amplio del texto en el que se insertan); igualmente, encontramos un conjunto de unidades de entonación que no realizan una unidad de información, como es el caso de los marcadores y de las unidades que presentan una forma de la planificación oral