Aplicación de la Bioquímica y Biología Molecular en el Grado de Enfermería a través del aprendizaje basado en problemas

El CMD docente (CMD) se ha realizado en la asignatura de 1er curso “Bioquímica y Biología Molecular”. Se ha desarrollado incluyendo el temario correspondiente al bloque de Proteínas. Han participado 56 estudiantes. El trabajo se ha realizado, inicialmente individual y fuera del aula, aunque algunos optaron por hacerlo conjunto, en subgrupos y con un aprendizaje colaborativo. Se han empleado los mapas de contenidos y se ha evaluado el CMD mediante el uso de escaleras de aprendizaje. Los resultados muestran, en general, una adquisición adecuada de los conocimientos trabajados y han sido bastante satisfactorios para el alumnado

Different genetic requirements for repair of replication-born double-strand breaks by sister-chromatid recombination and break-induced replication

Homologous recombination (HR) is the major mechanism used to repair double-strand breaks (DSBs) that result from replication, but a study of repair of DSBs specifically induced during S-phase is lacking. Using an inverted-repeat assay in which a DSB is generated by the encountering of the replication fork with nicks, we can physically detect repair by sister-chromatid recombination (SCR) and intra-chromatid break-induced replication (IC-BIR). As expected, both events depend on Rad52, but, in contrast to previous data, both require Rad59, suggesting a prominent role of Rad59 in repair of replication-born DSBs. In the absence of Rad51, SCR is severely affected while IC-BIR increases, a phenotype that is also observed in the absence of Rad54 but not of its paralog Rdh54/Tid1. These data are consistent with SCR occurring by Rad51-dependent mechanisms assisted by Rad54, and indicate that in the absence of strand exchange-dependent SCR, breaks can be channeled to IC-BIR, which works efficiently in the absence of Rad51. Our study provides molecular evidence for inversions between repeats occurring by BIR followed by single-strand annealing (SSA) in the absence of strand exchange

Control of the function of the transcription and repair factor TFIIH by the action of the cochaperone Ydj1

Yeast rad3-102, a mutant of the TFIIH complex involved in nucleotide excision repair (NER) and transcription, can perform NER initial steps but not late steps of postincision gap filing. Because removal of early-acting NER proteins prevents rad3-102 deleterious action, we used this feature to explore if chaperones act in early NER. We found that the cochaperone Ydj1 is required for NER and that Ydj1 guarantees TFIIH stoichiometry. Importantly, in the absence of Ydj1, the roles of TFIIH in transcription and transactivation, the ability to activate transcription by nuclear receptors in response to hormones, are strongly impaired. We propose that TFIIH constitutes a multitarget complex for Ydj1, as six of the seven TFIIH core components contain biologically relevant Ydj1- binding motives. Our results provide evidence for a role of chaperones in NER and transcription, with implications in cancer and TFIIH-associated syndromes

Control of the function of the transcription and repair factor TFIIH by the action of the cochaperone Ydj1

Yeast rad3-102, a mutant of the TFIIH complex involved in nucleotide excision repair (NER) and transcription, can perform NER initial steps but not late steps of postincision gap filing. Because removal of early-acting NER proteins prevents rad3-102 deleterious action, we used this feature to explore if chaperones act in early NER. We found that the cochaperone Ydj1 is required for NER and that Ydj1 guarantees TFIIH stoichiometry. Importantly, in the absence of Ydj1, the roles of TFIIH in transcription and transactivation, the ability to activate transcription by nuclear receptors in response to hormones, are strongly impaired. We propose that TFIIH constitutes a multitarget complex for Ydj1, as six of the seven TFIIH core components contain biologically relevant Ydj1- binding motives. Our results provide evidence for a role of chaperones in NER and transcription, with implications in cancer and TFIIH-associated syndromes

Conditional Expression of RNase P in the CyanobacteriumSynechocystis sp. PCC6803 Allows Detection of Precursor RNAs

We have constructed a strain (CT1) that expresses RNase P conditionally with the aim to analyze the in vivotRNA processing pathway and the biological role that RNase P plays inSynechocystis 6803. In this strain, the rnpBgene, coding for the RNA subunit of RNase P, has been placed under the control of the petJ gene promoter (PpetJ), which is repressed by copper, cell growth, and accumulation of RNase P RNA is inhibited in CT1 after the addition of copper, indicating that the regulation by copper is maintained in the chimerical PpetJ -rnpB gene and that RNase P is essential for growth in Synechocystis. We have analyzed several RNAs by Northern blot and primer extension in CT1. Upon addition of copper to the culture medium, precursors of the mature tRNAs are detected. Furthermore, our results indicate that there is a preferred order in the action of RNase P when it processes a dimeric tRNA precursor. The precursors detected are 3′-processed, indicating that 3′ processing can occur before 5′ processing by RNase P. The size of the precursors suggests that the terminal CCA sequence is already present before RNase P processing. We have also analyzed other potential RNase P substrates, such as the precursors of tmRNA and 4.5 S RNA. In both cases, accumulation of larger than mature size RNAs is observed after transferring the cells to a copper-containing medium

Interdependence of the Rad50 hook and globular domain functions

Rad50 contains a conserved Zn2+ coordination domain (the Rad50 hook) that functions as a homodimerization interface. Hook ablation phenocopies Rad50 deficiency in all respects. Here we focused on rad50 mutations flanking the Zn2+-coordinating hook cysteines. These mutants impaired hook-mediated dimerization, but recombination between sister chromatids was largely unaffected. This may reflect that cohesin-mediated sister chromatid interactions are sufficient for double strand break repair. However, Mre11 complex functions specified by the globular domain, including Tel1 (ATM) activation, nonhomologous end-joining, and DNA double strand break end resection were affected, suggesting that dimerization exerts a broad influence on Mre11 complex function. These phenotypes were suppressed by mutations within the coiled coil and globular ATPase domain, suggesting a model in which conformational changes in the hook and globular domains are transmitted via the extended coils of Rad50. We propose that transmission of spatial information in this manner underlies the regulation of Mre11 complex functions

The Rad50 coiled-coil domain is indispensable for Mre11 complex functions

The Mre11 complex (Mre11, Rad50 and Xrs2 in Saccharomyces cerevisiae) influences diverse functions in the DNA damage response. The complex comprises the globular DNA-binding domain and the Rad50 hook domain, which are linked by a long and extended Rad50 coiled-coil domain. In this study, we constructed rad50 alleles encoding truncations of the coiled-coil domain to determine which Mre11 complex functions required the full length of the coils. These mutations abolished telomere maintenance and meiotic double-strand break (DSB) formation, and severely impaired homologous recombination, indicating a requirement for long-range action. Nonhomologous end joining, which is probably mediated by the globular domain of the Mre11 complex, was also severely impaired by alteration of the coiled-coil and hook domains, providing the first evidence of their influence on this process. These data show that functions of Mre11 complex are integrated by the coiled coils of Rad50.Swiss National Science Foundation and Eugen and Elisabeth Schellenberg Foundation GM56888, PBZH33-112756, PA0033-117484Ministerio de Ciencia e Innovación BFU2006-05260, 2010 CSD2007-01

Transvaginal Ultrasound Accuracy in the Hydrosalpinx Diagnosis: A Systematic Review and Meta-Analysis

Hydrosalpinx is a condition with a crucial prognostic role in reproduction, and its diagnosis by a non-invasive technique such as ultrasound is key in achieving an adequate reproductive assessment while avoiding unnecessary laparoscopies. The aim of the present systematic review and meta-analysis is to synthetize and report the current evidence on transvaginal sonography (TVS) accuracy to diagnose hydrosalpinx. Articles on the topic published between January 1990 and December 2022 were searched in five electronic databases. Data from the six selected studies, comprising 4144 adnexal masses in 3974 women, 118 of which were hydrosalpinxes, were analyzed as follows: overall, TVS had a pooled estimated sensitivity for hydrosalpinx of 84% (95% confidence interval (CI) = 76-89%), specificity of 99% (95% CI = 98-100%), positive likelihood ratio of 80.7 (95% CI = 33.7-193.0), and negative likelihood ratio of 0.16 (95% CI = 0.11-0.25) and DOR of 496 (95% CI = 178-1381). The mean prevalence of hydrosalpinx was 4%. The quality of the studies and their risk of bias were assessed using QUADAS-2, evidencing an overall acceptable quality of the selected articles. We concluded that TVS has a good specificity and sensitivity for diagnosing hydrosalpinx

PROTOTYPING A PIEZOELECTRIC ENERGY-HARVESTING SYSTEM FROM THE SIMULATED MECHANICAL PULSATION OF A 3D-PRINTED HEART MODEL

Gemstone Team CARDIOIndividuals have to frequently undergo pacemaker replacement surgeries increasing the chance of surgical complications. A system was developed for an alternative energy source for pacemaker technology. We aimed to capture energy from the mechanical pulsation of a 3D-printed synthetic heart - as a viable simulation of a functional adult heart - using different types of piezoelectric materials. Our study evaluated maximum voltage captured by piezoelectric materials from pulsatile stimulation of the heart model. Initial tests generated 9V, suggesting that piezoelectric material is an adequate alternative energy source for pacemakers. Future investigation will aim to optimize the electrical and mechanical parameters of our system, laying the foundation for the development of a “heart-powered pacemaker.” Our research investigates the feasibility and mechanisms associated with harvesting mechanical motion from the heart itself, converting it into usable electrical energy, and evaluating whether this captured and converted energy is sufficient to power a commercially used cardiac pacemaker

Efficacy of bortezomib in sarcomas with high levels of MAP17 (PDZK1IP1

Sarcomas are malignant tumors accounting for a high percentage of cancer morbidity and mortality in children and young adults. Surgery and radiation therapy are the accepted treatments for most sarcomas; however, patients with metastatic disease are treated with systemic chemotherapy. Many tumors display marginal levels of chemoresponsiveness, and new treatment approaches are needed. MAP17 is a small non-glycosylated membrane protein overexpressed in carcinomas. The levels of MAP17 could be used as a prognostic marker to predict the response to bortezomib in hematological malignancies and in breast tumors. Therefore, we analyzed the expression of this oncogene in sarcomas and its relationship with clinico-pathological features, as well as tested whether it can be used as a new biomarker to predict the therapeutic response to bortezomib and new therapies for sarcomas. We found that the levels of MAP17 were related to clinical features and poor survival in a cohort of 69 patients with different sarcoma types, not being restricted to any special subtype of tumor. MAP17 expression is associated with poor overall survival (p<0.001) and worse disease-free survival (p=0.002). Cell lines with high levels of MAP17 show a better response to bortezomib in vitro. Furthermore, patient-derived xenografts (PDX) with high levels of MAP17 respond to bortezomib in vivo. Our results showed that this response is due to the lower levels of NFκB and autophagy activation. Therefore, we suggest that MAP17 is a new biomarker to predict the efficacy of bortezomib as a new therapy for sarcomas.España, Consejeria de Ciencia e innovación CTS-6844 and CTS-1848Andalucia, Consejería de Salud PI-0029-2013Andalucia, Consejería de Salud PI-0096-2014Andalucia, Consejería de Salud PI-0306-201