Identification of new molecular targets for personalized therapy in pediatric patients with inflammatory bowel disease (IBD)

Le malattie infiammatorie corniche intestinali (MICI) sono un gruppo di malattie infiammatorie immunomediate che comprendono il morbo di Crohn e la rettocolite ulcerosa. Nella popolazione pediatrica le MICI sono di particolare interesse a causa della aumentata incidenza della malattia e, sebbene siano stati sviluppati diversi approcci terapeutici, \ue8 molto difficile individuare il trattamento ottimale. I glucocorticoidi (GC) sono farmaci prescritti per indurre la remissione ma alcuni pazienti risultano resistenti al trattamento o richiedono terapie prolungate e tali pazienti sono soggetti a numerosi reazioni avverse. Il long non-coding RNA (lncRNA) growth-arrest specific 5 (GAS5) interagisce con il complesso GC-recettore dei glucocorticoidi (GR) inibendo l\u2019attivit\ue0 trascrizionale dei geni responsivi ai GC. La prima parte del mio progetto di tesi si occupa di studiare il ruolo di GAS5 come marker molecolare della resistenza farmacologica ai GC. L\u2019associazione tra il lncRNA e l\u2019efficacia degli steroidi, espressa in termini di inibizione della proliferazione, \ue8 stata valutata su due linee cellulari tumorali di colon e ovaio che sono state identificate rispettivamente come modello di resistenza e sensibilit\ue0 farmacologica ai GC. Inoltre, il ruolo di GAS5 \ue8 stato osservato nelle cellule mononucleate del sangue periferico di pazienti pediatrici affetti da MICI sia alla diagnosi che dopo 4 settimane di trattamento con GC; una maggiore espressione di GAS5 \ue8 stata osservata nei pazienti con una risposta sfavorevole agli steroidi. Questi risultati preliminari indicano che GAS5 potrebbe essere considerato un nuovo biomarker di resistenza farmacologica ai GC. I livelli di espressione di GAS5 sono stati valutati anche nelle biopsie di colon di pazienti pediatrici affetti da MICI anche rispetto ai livelli di espressione proteica e genica di due metalloproteasi (MMP) coinvolte nel danno tissutale. La downregolazione di GAS5 osservata nei tessuti infiammati rispetto ai tessuti non infiammati \ue8 inversamente correlata all\u2019espressione delle MMP suggerendo che il lncRNA potrebbe controllare l\u2019attivit\ue0 di queste proteine. Nella seconda parte del mio progetto di tesi abbiamo valutato i livelli di espressione proteica della tristetraprolin (TTP) nelle MICI. La TTP e una proteina zinc finger capace di interagire e inibire le citochine pro-infiammatorie attraverso il legame con gli elementi ricchi di AU sul 3\u2019 UTR degli mRNA target. Abbiamo considerato anche il ruolo della sua fosforilazione, poich\ue9 questa modificazione post-traduzionale interferisce con l\u2019attivit\ue0 della TTP che in questo stato \ue8 responsabile della stabilizzazione delle citochine d\u2019interesse. L\u2019espressione proteica della TTP \ue8 stata valutata nei tessuti di colon e nei macrofagi dei pazienti pediatrici affetti da MICI. L\u2019espressione della TTP risulta upregolata sia nei tessuti di colon che nei macrofagi. I risultati inoltre confermano il coinvolgimento della fosforilazione nell\u2019attivit\ue0 della TTP. Questi risultati preliminari, se confermati con ulteriori esperimenti, potrebbero aprire nuove prospettive nello studio delle IBD e nella formulazione di una nuova terapia farmacologica mirata in grado di modulare la fosforilazione della TTP attraverso l\u2019uso di fosfatasi e favorire cos\uec la degradazione delle citochine pro-infiammatorie.Inflammatory bowel disease (IBD) is a chronic immune-mediated condition of the gastrointestinal tract that includes Crohn disease and ulcerative colitis. Pediatric IBDs are of particular interest since their incidence is rising and, even if different pharmacological strategies are used, the optimal treatment is far from being achieved. Glucocorticoid (GCs) are prescribed for inducing remission but there is a high risk of adverse effects especially in subjects that poorly respond to these agents and require long treatments. The long non-coding RNA (lncRNA) growth arrest-specific 5 (GAS5) interacts with the activated glucocorticoid receptor (GR), inhibiting the transcription of GCs responsive genes. The first part of my thesis project is focused on the study of GAS5 as a molecular marker of GCs resistance. We evaluated the association between the lncRNA and the efficacy of steroids, in terms of inhibition of proliferation, in two immortalized cell lines from colon and ovarian cancers, a GC-resistant and GC-sensitive model, respectively. After GCs treatment in the GC-resistant cells GAS5 upregulation was observed and, in response to the drug, the lncRNA accumulated more in the cytoplasm compared to the nucleus. Furthermore, we evaluated GAS5 levels in the peripheral blood mononuclear cells of pediatric IBD patients at diagnosis and after 4 weeks of GCs administration. Gene expression analysis have shown an upregulation of the lncRNA in patients with unfavourable steroid response. These preliminary results suggest that GAS5 could be considered a novel pharmacogenomic marker useful for the personalization of GC therapy. GAS5 expression was also measured in IBD patients\u2019 colon biopsies and its levels have been evaluated with respect to the gene and protein expression of two metalloproteinases (MMP-2, MMP-9) involved in tissue damage in IBDs. The GAS5 downregulation observed in inflamed tissues compared with the non-inflamed one is inversely related to MMPs expression suggesting a role of this lncRNA in controlling the activity of these molecules. In the second part of my thesis project we evaluated the role of the tristetraprolin (TTP) protein in IBDs. TTP is a zinc finger protein able to interact and inhibit pro-inflammatory cytokines through the binding with AU-rich elements on the 3\u2019 untranslated region on mRNA. The role of phosphorylation on TTP activity was also evaluated, since this post-translational modification could impair protein activity and consequently the stabilization of cytokines levels. TTP protein expression was studied in pediatric IBDs patients\u2019 colon tissues and in macrophages differentiated from peripheral blood mononuclear cells. An upregulation of TTP expression in both inflamed colon tissues and in macrophages of IBD patients was observed, and was closely related to the phosphorylation of the protein. These preliminary results, if confirmed with further experiments, could open new perspectives in the study of IBDs and in the investigation of new target therapy based on the modulation of TTP phosphorylation by phosphatases to favour pro-inflammatory cytokines degradation

Long Noncoding RNA GAS5: A Novel Marker Involved in Glucocorticoid Response

Glucocorticoids (GCs) exert their effects through regulation of gene expression after activation in the cytoplasm of the glucocorticoid receptor (GR) encoded by NR3C1 gene. A negative feedback mechanism resulting in GR autoregulation has been demonstrated through the binding of the activated receptor to intragenic sequences called GRE-like elements, contained in GR gene. The long noncoding RNA growth arrest-specific transcript 5 (GAS5) interacts with the activated GR suppressing its transcriptional activity. The aim of this study was to evaluate the possible role of GAS5 and NR3C1 gene expression in the antiproliferative effect of methylprednisolone in peripheral blood mononuclear cells and to correlate the expression with individual sensitivity to GCs. Subjects being poor responders to GCs presented higher levels of GAS5 and NR3C1 in comparison with good responders. We suggest that abnormal levels of GAS5 may alter GC effectiveness, probably interfering with the mechanism of GR autoregulation

Carbamazepine-induced thrombocytopenic purpura in a child: Insights from a genomic analysis

To the Editor, Carbamazepine is an effective anticonvulsant and has a relatively low incidence of adverse effects, although it occasionally causes hema- tologic disorders. We herein describe a patient with carbamazepine- induced thrombocytopenic purpura that was investigated by pharma- cological, immunological and genomic assays

Com millorar la motivació dels estudiants en assignatures de perfil economètric? una mesura pràctica amb avaluació empírica de la seva efectivitat

Projecte: 2015PID-UB/013El projecte s’ha aplicat als alumnes de les assignatures obligatòries d’Econometria I i II del Grau d’Economia de la Facultat d’Economia i Empresa al curs 2015-2016. Atesos els problemes de motivació habituals que presenten els alumnes del nostre Grau, especialment en matèries de perfil quantitatiu, el projecte ha perseguit l’objectiu general de fomentar la motivació del estudiants i l’aprenentatge actiu dels mateixos. Per tal d’aconseguir-ho vam pensar que seria possible incrementar aquesta motivació si els propis alumnes fossin la mostra estadística per l’anàlisi i aplicació de les tècniques economètriques ensenyades a classe. Així, es va pretendre motivar la participació dels alumnes mitjançant la reflexió sobre els factors determinants teòrics del seu propi rendiment acadèmic. Per fer-ho, s’ha recollit en primer lloc una base de dades dels propis alumnes sobre el seu rendiment acadèmic i les seves característiques sociodemogràfiques i familiars. Posteriorment, els alumnes han emprat aquesta base de dades per tal de construir un model economètric a partir del qual han aplicat les eines estadístic-economètriques estudiades a classe per tal d’aconseguir explicar el seu rendiment acadèmic. Atès que ells mateixos han estat la mostra d’anàlisi i el tema a analitzar era del seu interès, la participació ha estat molt elevada. Els resultats finals han sigut positius ja que ha incrementat la participació a classe i la reflexió conjunta del tema analitzat tant des d’un punt de vista teòric com aplicat. Alhora, han millorat els rendiment acadèmic general

Por qué el desconfinamiento asimétrico es una buena idea

A lo largo del mes de marzo y principios del mes de abril de este año la epidemia de COVID-19 se transmitió de manera exponencial entre la población de Cataluña, con una ralentización en días posteriores posiblemente asociada a la implantación del confinamiento de la población

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements