Mecanismes de senyalització intracel·lular regulats per la proteïna p19 H-Ras

Consultable des del TDXTítol obtingut de la portada digitalitzadac-H-ras és un gen essencial per a varis processos del cicle cel·lular com són la proliferació cel·lular, aturada del cicle, diferenciació i apoptosis. El seu paper com a oncogen és degut al fet que es presenta mutat en un 30% dels tumors testats i que a més a més s'han demostrat correlacions entre la presència de mutacions i capacitat transformant. El producte del gen c-H-ras és la proteïna p21, que es troba ancorada a la part interna de la membrana plasmàtica i transdueix les senyals extracel·lulars mitjançant canvis de la seva estructura, dramàticament regulats per intercanvi de GDP a GTP (i al contrari). El canvi d'estructura de p21 cap a la forma activa, amb més GTP unit, provoca que la zona efectora de p21 sigui accessible a varis efectors que són el punt de partida d'una cascada d'interaccions que com a últim terme regularan el cicle cel·lular cap a una situació determinada. El nostre grup d'investigació ha descrit que el gen c-H-ras codifica per una segona proteïna, p19, producte de splicing alternatiu, que es troba entre el citoplasma i el nucli. Degut que p19 no es troba ancorada a la membrana plasmàtica i que a més a més només presenta una activitat residual unidora a GTP, se suposa que aquesta nova proteïna exerceix una funció complementària del gen c-H-ras, que en altres paraules indicaria que la funció d'aquest gen es porta a terme per l'acció de dues proteïnes amb localització cel·lular diferent. Per tant, els nostres objectius han estat estudiar la localització, funció i regulació de la proteïna p19 H-Ras en funció de diferents factors proteics que interaccionen amb ella. Al mateix temps, s'han realitzat estudis que demostren la regulació de l'expressió i activació de varis factors implicats en la via del complex d'esclerosi tuberosa (Tuberous Sclerosis Complex, TSC) o via de mTOR, per part de p19. Per fer-ho s'ha utilitzat un ampli ventall de tècniques moleculars, com les PCR en temps real, els microarrays d'ADN, o assajos de cicle cel·lular, entre d'altres. Les nostres investigacions han revelat que la proteïna p19 regula TCTP, un factor amb activitat GEF (guanine exchange factor) envers Rheb, així com hipo- i hiperfosforila Akt i ERK, respectivament, dos inhibidors del complex TSC. Hem proposat que la funció de p19 en la via TSC és regular la fosforilació de p70S6K. A més a més, hem observat que p19 indueix l'expressió dels miRNAs miR-342, miR-206, miR-330, miR-138 i miR-99b. D'altra banda, la proteïna p19 indueix una aturada del cicle cel·lular en la fase G1, efecte que s'atenua parcialment quan inhibim el miR-206. També hem observat la interacció de p19 amb la proteïna p73 tot incrementant l'activitat telomerasa, però no amb p53. De forma interessant, p19 estimula l'expressió de FoxO, aspecte que juntament amb l'aturada en G1/S i la hipofosforilació d'Akt i p70 S6K, dóna lloc al manteniment d'un estat de quiescència reversible, tot prevenint una entrada en el procés d'apoptosi.c-H-ras is an essential gene for many processes such as proliferation, cycle arrest, differentiation and apoptosis. Its role as an oncogene is due to the fact that it is mutated in 30% of the tumors tested, and that also have shown correlations between the presence of mutations and transforming ability of cancer cells. The product of the c-H-ras gene is the p21 protein, which is anchored on the inner side of the plasma membrane and controles extracellular signals through changes in its structure, dramatically regulated by the exchange of GDP for GTP. The change of structure of p21 into the active form, coupled with GTP, promotes the interaction of p21 to several effectors, which are the starting point for a cascade of interactions that will regulate the cell cycle. Our research group has reported that the c-H-ras gene encodes for a second protein, p19, a product of alternative splicing, which is located between the nucleus and cytoplasm. Due to the fact that p19 is not anchored in the plasma membrane and that also only has a residual GTP-dependent activity, it is assumed that this protein plays a complementary role of the c-H-ras gene. Therefore, our objectives have been the study of location, function and regulation of the p19 protein based on various factors that interact with it. At the same time, we performed assays that show the regulation of the expression and activation of several factors involved in the path of tuberous sclerosis complex (Tuberous Sclerosis Complex, TSC) or mTOR pathway by P19. To do this we have used used a wide range of molecular techniques, such as real-time PCR, the DNA microarrays, or cell cycle assays. Our investigations have revealed that the p19 protein regulates TCTP, a factor with GEF activity (guanine exchange factor) towards Rheb, as well as hypo-and hiper-phosphorilates Akt and ERK, respectively, two inhibitors of the complex TSC. We have proposed that the role of p19 in the TSC is regulated through phosphorylation of p70S6K. In addition, we found that p19 induces the expression of miRNAs miR-342, miR-206, miR-330, miR-138 and mir-99b. On the other hand, the p19 protein induces a cell cycle arrest in the G1 phase, effect that is partially attenuated whit the inhibition of miR-206. We have also observed the interaction of p19 and p73 protein increasing telomerase activity, but not with p53. Interestingly, p19 stimulates the expression of FoxO, something that along with the arrest in G1 / S and hipo-phosphorylation of Akt and p70 S6K, given rise to the maintenance of a reversible state of quiescence, but preventing an entry in apoptosis

A New MAMLD1 Variant in an Infant With Microphallus and Hypospadias With Hormonal Pattern Suggesting Partial Hypogonadotropic Hypogonadism—Case Report

MAMLD1 gene; Hypospadias; MinipubertyGen MAMLD1; Hipospàdies; MinipubertatGen MAMLD1; Hipospadias; MinipubertadMAMLD1 (X chromosome) is one of the recognized genes related to different sex development. It is expressed in testis and ovaries and seems to be involved in fetal sex development and in adult reproductive function, including testosterone biosynthesis. However, its exact role remains unclear. Over 40 genetic variants have been described, mainly in male individuals and mostly associated with hypospadias. Although MAMLD1 has been shown to regulate the expression of the steroidogenic pathway, patients with MAMLD1 variants mostly show normal gonadal function and normal testosterone levels. Here we describe a patient (46,XY) with hypospadias and microphallus, with low testosterone and dihydrotestosterone (DHT) levels, and with inappropriately low values of luteinizing hormone (LH) during minipuberty. This hormonal pattern was suggestive of partial hypogonadotropic hypogonadism. A stimulation test with hCG (4 months) showed no significant increase in both testosterone and dihydrotestosterone concentrations. At 5 months of age, he was treated with intramuscular testosterone, and the penis length increased to 3.5 cm. The treatment was stopped at 6 months of age. Our gonadal function massive-sequencing panel detected a previously unreported nonsense variant in the MAMLD1 gene (c.1738C>T:p.Gln580Ter), which was classified as pathogenic. This MAMLD1 variant, predicting a truncated protein, could explain his genital phenotype. His hormonal profile (low testosterone, dihydrotestosterone, and LH concentrations) together with no significant increase of testosterone and DHT plasma concentrations (hCG test) highlight the potential role of this gene in the biosynthesis of testosterone during the fetal stage and minipuberty of the infant. Besides this, the LH values may suggest an involvement of MAMLD1 in the LH axis or a possible oligogenesis. It is the first time that a decrease in DHT has been described in a patient with an abnormal MAMLD1

Novel variant in HHAT as a cause of different sex development with partial gonadal dysgenesis associated with microcephaly, eye defects, and distal phalangeal hypoplasia of both thumbs: Case report

Different sexual development; Minigene studiesDesarrollo sexual diferente; Estudios de minigenesDesenvolupament sexual diferent; Estudis minigènicsThe palmitoylation of the Hedgehog (Hh) family of morphogens, named sonic hedgehog (SHH), desert hedgehog (DHH), and Indian hedgehog (IHH), is crucial for effective short- and long-range signaling. The hedgehog acyltransferase (HHAT) attaches the palmitate molecule to the Hh; therefore, variants in HHAT cause a broad spectrum of phenotypes. A missense HHAT novel variant c.1001T>A/p.(Met334Lys) was described in a patient first referred for a 46,XY different sexual development with partial gonadal dysgenesis but with microcephaly, eye defects, and distal phalangeal hypoplasia of both thumbs. The in silico analysis of the variant predicted an affectation of the nearest splicing site. Thus, in vitro minigene studies were carried out, which demonstrated that the variant does not affect the splicing. Subsequent protein in silico studies supported the pathogenicity of the variant, and, in conclusion, this was considered the cause of the patient’s phenotype.This study was partly supported by a grant from the Fondo de Investigación Sanitaria (PI15/01647 [to MF-C and SB-S])

Genetic reanalysis of patients with a difference of sex development carrying the NR5A1/SF-1 variant p.Gly146Ala has discovered other likely disease-causing variations.

NR5A1/SF-1 (Steroidogenic factor-1) variants may cause mild to severe differences of sex development (DSD) or may be found in healthy carriers. The NR5A1/SF-1 c.437G>C/p.Gly146Ala variant is common in individuals with a DSD and has been suggested to act as a susceptibility factor for adrenal disease or cryptorchidism. Since the allele frequency is high in the general population, and the functional testing of the p.Gly146Ala variant revealed inconclusive results, the disease-causing effect of this variant has been questioned. However, a role as a disease modifier is still possible given that oligogenic inheritance has been described in patients with NR5A1/SF-1 variants. Therefore, we performed next generation sequencing (NGS) in 13 DSD individuals harboring the NR5A1/SF-1 p.Gly146Ala variant to search for other DSD-causing variants and clarify the function of this variant for the phenotype of the carriers. Panel and whole-exome sequencing was performed, and data were analyzed with a filtering algorithm for detecting variants in NR5A1- and DSD-related genes. The phenotype of the studied individuals ranged from scrotal hypospadias and ambiguous genitalia in 46,XY DSD to opposite sex in both 46,XY and 46,XX. In nine subjects we identified either a clearly pathogenic DSD gene variant (e.g. in AR) or one to four potentially deleterious variants that likely explain the observed phenotype alone (e.g. in FGFR3, CHD7). Our study shows that most individuals carrying the NR5A1/SF-1 p.Gly146Ala variant, harbor at least one other deleterious gene variant which can explain the DSD phenotype. This finding confirms that the NR5A1/SF-1 p.Gly146Ala variant may not contribute to the pathogenesis of DSD and qualifies as a benign polymorphism. Thus, individuals, in whom the NR5A1/SF-1 p.Gly146Ala gene variant has been identified as the underlying genetic cause for their DSD in the past, should be re-evaluated with a NGS method to reveal the real genetic diagnosis

P19 H-Ras Induces G1/S Phase Delay Maintaining Cells in a Reversible Quiescence State

This is an open-access article distributed under the terms of the Creative Commons Attribution License.[Background]: Three functional c-ras genes, known as c-H-ras, c-K-ras, and c-N-ras, have been largely studied in mammalian cells with important insights into normal and tumorigenic cellular signal transduction events. Two K-Ras mRNAs are obtained from the same pre-mRNA by alternative splicing. H-Ras pre-mRNA can also be alternatively spliced in the IDX and 4A terminal exons, yielding the p19 and p21 proteins, respectively. However, despite the Ras gene family’s established role in tumorigenic cellular signal transduction events, little is known about p19 function. Previous results showed that p19 did not interact with two known p21 effectors, Raf1 and Rin1, but was shown to interact with RACK1, a scaffolding protein that promotes multi-protein complexes in different signaling pathways (Cancer Res 2003, 63 p5178). This observation suggests that p19 and p21 play differential and complementary roles in the cell.[Principal Findings]: We found that p19 regulates telomerase activity through its interaction with p73a/b proteins. We also found that p19 overexpression induces G1/S phase delay; an observation that correlates with hypophosphorylation of both Akt and p70SK6. Similarly, we also observed that FOXO1 is upregulated when p19 is overexpressed. The three observations of (1) hypophosphorylation of Akt, (2) G1/S phase delay and (3) upregulation of FOXO1 lead us to conclude that p19 induces G1/S phase delay, thereby maintaining cells in a reversible quiescence state and preventing entry into apoptosis. We then assessed the effect of p19 RNAi on HeLa cell growth and found that p19 RNAi increases cell growth, thereby having the opposite effect of arrest of the G1/S phase or producing a cellular quiescence state.[Significance]: Interestingly, p19 induces FOXO1 that in combination with the G1/S phase delay and hypophosphorylation of both Akt and p70SK6 leads to maintenance of a reversible cellular quiescence state, thereby preventing entry into apoptosis.This work was supported by Fundacion de Investigacion Medica Mutua Madrileña Automovilista (Fundacion MMA), the Plan Nacional (MEC) BFU2005-00701 and the Fundacion Eugenio Rodriguez Pascual. M.C. was a recipient of a Fmed MMA fellowship.Peer reviewe

Incidència de diferents modalitats de tutoria per petits grups en els aprenentatges dels estudiants

S'ha analitzat la incidència de tres modalitats de tutoria (presencial planificada i obligatòria; no presencial planificada i obligatòria; presencial oberta i a demanda) sobre les qualificacions en treballs escrits d'activitats grupals, en tres assignatures obligatòries del grau de Psicologia. Globalment, trobem diferències significatives a favor de les tutories presencials, planificades i obligatòries, i del caràcter planificat i obligatori, però no en totes les assignatures

GIDC en psicologia del desenvolupament

Podeu consultar la Setena trobada de professorat de Ciències de la Salut completa a: http://hdl.handle.net/2445/4335

Sphingosine-1-phosphate lyase mutations cause primary adrenal insufficiency and steroid-resistant nephrotic syndrome

Primary adrenal insufficiency is life threatening and can present alone or in combination with other comorbidities. Here, we have described a primary adrenal insufficiency syndrome and steroid-resistant nephrotic syndrome caused by loss-of-function mutations in sphingosine-1-phosphate lyase (SGPL1). SGPL1 executes the final decisive step of the sphingolipid breakdown pathway, mediating the irreversible cleavage of the lipid-signaling molecule sphingosine-1-phosphate (S1P). Mutations in other upstream components of the pathway lead to harmful accumulation of lysosomal sphingolipid species, which are associated with a series of conditions known as the sphingolipidoses. In this work, we have identified 4 different homozygous mutations, c.665G>A (p.R222Q), c.1633_1635delTTC (p.F545del), c.261+1G>A (p.S65Rfs*6), and c.7dupA (p.S3Kfs*11), in 5 families with the condition. In total, 8 patients were investigated, some of whom also manifested other features, including ichthyosis, primary hypothyroidism, neurological symptoms, and cryptorchidism. Sgpl1-/- mice recapitulated the main characteristics of the human disease with abnormal adrenal and renal morphology. Sgpl1-/- mice displayed disrupted adrenocortical zonation and defective expression of steroidogenic enzymes as well as renal histology in keeping with a glomerular phenotype. In summary, we have identified SGPL1 mutations in humans that perhaps represent a distinct multisystemic disorder of sphingolipid metabolism

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

Disseny de miniunitats didàctiques de l'àrea de llengües estrangeres : anglès

Resumen basado en el de la autora en catalán. No consta el centro realizadorEl trabajo se basa en el diseño de siete guiones de miniunidades didácticas (MUD) del área de lenguas extranjeras: inglés y de las guías didácticas correspondientes. La estructura de estos siete guiones de miniunidades didácticas es la siguiente: presentación, práctica y evaluación sumativa. Tienen en cuenta la concepción constructivista del aprendizaje y el nuevo entorno que comporta la sociedad de la información.Generalitat de Catalunya. Departament d'EnsenyamentCataluñaES