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12:00 – 12:30 Ana Sánchez

Circulating miRNAs profiling in plasma as biomarkers in Wilson disease

Wilson disease (WD) is an inherited disorder of copper metabolism caused by mutations in ATP7B, encoding for a liver copper-transporting protein. ATP7B dysfunction results in a deficit in biliary copper excretion and a progressive accumulation of this metal in the organism, mainly in liver and brain. As WD is a treatable disorder, to achieve an early definitive diagnosis in patients is required; otherwise, it could become in a poor prognosis condition. In this work, circulating miRNAs profiling in plasma has been accomplished to identify biomarkers that could serve to monitor disease progression in WD patients under chelation therapy. Initially, miRNA-seq was performed in a discovery cohort, identifying 18 miRNAs increased in plasma from patients. Five of them stood out, as they are involved in different aspects of liver disease (steatosis, inflammation and fibrosis), iron and lipids metabolism. Plasma levels of these five miRNAs were assessed by qPCR in samples from the discovery cohort and in an independent validation cohort. In both studies, it was confirmed that three of them were induced in plasma from WD patients and showed strong correlation with biochemical liver function markers. Logistic regression models for each miRNA were developed and exhibited good performance classifying patients with poor outcome factors. Finally, potential of these three miRNAs to be used in clinical follow-up was explored, verifying that increased circulating levels in patients are not eventual findings and are repeated over time.

12:30 – 13:00 Candela Machuca

Cerebellar Purkinje cell model generation based in iPSCs technology for the study of two rare neurodegenerative diseases: ARSACS and PLAN

Patient-derived induced pluripotent stem cells (iPSCs) provide an unprecedented opportunity to recapitulate disease pathogenicity without the need for genetic manipulation and creation of gene targeted animal models. New technologies with iPSCs are being developed to make human neurons and have the potential to improve our understanding underlying mechanisms of neurological diseases and development. Cerebellar atrophy is a condition associated with neurodegenerative diseases such as Charlevoix-Saguenay’s Recessive Spastic Ataxia (ARSACS) and PLA2G6-Associated Neurodegeneration (PLAN). ARSACS is an early onset neurodegenerative disorder caused by mutations in the SACS gene, characterized with atrophy in superior cerebellum. PLAN, a NBIA (Neurodegeneration Brain Iron Accumulation) form due to mutations in PLA2G6, is a neuroaxonal dystrophy, which presents cerebellar ataxia. Our aim was to generate a cerebellar Purkinje cell model that will be used as models to investigate the cerebellar neurodegeneration to achieve a rationale therapy. We have developed a differentiation protocol using fibroblasts reprogrammed using Sendai virus to iPSCs, from ARSACS and PLAN patients. For both patients, we derived cerebellar precursors and mature Purkinje cells from iPSCs. Early and late cerebellar markers are being analyzed by molecular techniques. Moreover, functional comparative and electrophysiology analysis with the model are on-going to get a better characterization to gain and insight into the mechanisms of the diseases.

Effects of developmental alcohol exposure on sensory processing
Alexandre Medina, Associate Professor, Department of Pediatrics, University of Maryland, School of Medicine. Baltimore, USA.

Fetal alcohol spectrum disorders (FASD) are caused by gestational alcohol exposure and is the most common cause of preventable mental disability in the world. Recent epidemiological studies in the US, UK and Canada indicate a prevalence of 1-7% of all births. Children with FASD often present sensory alterations such as aversion to multiple sensory stimuli presented at the same time, attention deficits, poor visual-motor integration, delayed auditory processing and hypersensitivity to tactile stimulation. There is growing evidence supporting the idea that these problems in dealing with sensory processing give rise to social problems and learning deficits.

Sensory integration problems have long been associated with learning disabilities. In fact, it has been shown that performance in a multisensory integration task correlates with scores in a comprehensive IQ test in school age children. Furthermore, impaired multisensory processing has been implicated in the development of ADHD, schizophrenia, dyslexia, autism, and other poor cognitive outcomes.

Multisensory integration (MSI) can be seen at neuronal level, when the combination of stimulus from two or more sensory modalities leads to either facilitation or suppression of neuronal responses. It is thought that crossmodal facilitation can facilitate cognitive processes by increasing the speed and accuracy of perception and by improving attention. This is important not only during active learning tasks but is also crucial for the acquisition of intellectual abilities in school age children.

Animal models have been crucial to understand MSI and neuronal crossmodal facilitation and depression have been observed in mice, cats, ferrets and non-human primates. In the ferret, the rostral posterior parietal cortex (PPr) is a multisensory area that contains neurons activated by both visual and tactile stimulation.

Our overarching hypothesis is that gestational alcohol exposure disrupts MSI, reducing perception of important stimuli and contribute to cognitive and attention deficits seen in FASD. During my talk I will present recent studies from my lab testing the prediction that exposure to alcohol during the third trimester equivalent of human gestation impairs visual- tactile crossmodal facilitation in ferret PPr.

Defensa de Tesis Doctoral: “Aproximaciones moleculares para la identificación de nuevos biomarcadores y dianas terapéuticas del cáncer de pulmón no microcítico: células madre tumorales, transición epitelial-mesenquimal y modelos de xenoinjertos derivados de pacientes”

Doctorando: José Miguel Pardo Sánchez
Directora: Rosa Farràs Rivera
Tutor: José Ramón Murguía Ibáñez

El cáncer de pulmón es el tumor más frecuente y también el que presenta mayor mortalidad en términos absolutos, suponiendo hasta más del 18% de los fallecimientos por cáncer en el mundo al año. El cáncer de pulmón no microcítico (CPNM) representa casi el 85% de todos los tumores de pulmón. Tanto las alteraciones genéticas como la heterogeneidad y el microambiente tumoral influyen en la agresividad de los tumores de CPNM. Un factor que contribuye a la heterogeneidad tumoral es la presencia de células madre tumorales (CSC, Cancer Stem Cells). La metástasis y recurrencia tumoral después del tratamiento han sido atribuidas al crecimiento y supervivencia de esta subpoblación celular. La falta de marcadores específicos de CSC de pulmón representa una dificultad para identificarlas, y los marcadores de superficie conocidos hasta el momento no son válidos para separar poblaciones de CSC, por lo que se hace necesaria la generación de nuevos ensayos experimentales para aislar CSC de manera más robusta. La identificación de CSC podría ser la base para el diseño de nuevas estrategias terapéuticas personalizadas, basadas en la selección de una combinación más racional de fármacos, que tendría como objetivo eliminar la población de CSC en los tumores de CPNM.

Los objetivos de esta tesis doctoral han sido el aislamiento y caracterización de CSC derivadas de tumores de pacientes con CPNM, y de líneas de cultivo establecidas; la caracterización de proteínas involucradas en la transición epitelial mesenquimal (EMT) en CPNM que pueden ser relevantes para la adquisición y el mantenimiento de características de las células madre y para la progresión de la enfermedad; y el desarrollo de modelos experimentales de ratón a partir de xenoinjertos derivados de tumores de pacientes con CPNM (PDX) para la identificación de nuevos biomarcadores y para estudiar el fenotipo y evolución de los tumores de pacientes con CPNM.