Line 1. Dysfunction of nuclear RNA metabolism and actin cytoskeleton in motor neurons (MNs) and skeletal myofibers in spinal muscular atrophy (SMA). Response to treatment with ASO-nusinersen.
In collaboration with the Unit of Cellular Neurobiology of Prof. Jordi Calderó (IRB, Lleida) we are investigating the cellular bases of dysfunction of the metabolism of RNAs, in MNs, and of the actin cytoskeleton, in skeletal myofibers. We have recently shown that the motor neuron survival protein (SMN), whose coding gene (SMN1) is deleted or mutated in SMA, is a sarcomeric protein. The deficit of SMN in SMA produces very severe focal changes in the sarcomere architecture that affect the fine myofilaments of actin and compromise the contractile properties of myofibers. We are investigating the molecular mechanisms that regulate the dynamics of actin polymerization, particularly the RhoA-ROCK pathway, and its dysfunction in SMA. On the other hand, we are analyzing the effect of ASO-nusinersen (Biogen), a modulator of the splicing of the SMN2 gene, on the development, maturation of motor functions and survival of MNs in the NMA model of SMA. Preliminary results indicate that the intracerebroventricular administration of this ASO produces a spectacular rescue of motor functions and dysfunction of nuclear RNA metabolism in MNs. We are also analyzing the primary effect of nusinersen on skeletal myofibers, particularly in the rescue of muscular atrophy.
Line 2. Application of biopolymeric supports functionalized with graphene to develop in vitro models of neural differentiation.
In collaboration with the research group of Advanced Technologies and Bioprocesses (Dept. Chemical and Biomolecular Engineering, UC) we are analyzing the viability of various biopolymeric supports (“scaffolds”) of poly (ε-caprolactone) (PCL) or poly-acrylonitrile (PAN) functionalized with graphene to develop 2D (membrane) and 3D models with possible applications in the field of tissue engineering and neural differentiation. Membranes have been prepared and characterized with: i) scanning electron microscopy, ii) thermogravimetric analysis of thickness and porosity, iii) FT-IR and Raman spectroscopy and iv) analysis of electrical conductivity. Our preliminary results indicate that the amount and oxidation status of graphene incorporated into the "scaffolds" are determinants in the differentiation of NSC34 and C6 cell lines to motor neurons and astrocytes, respectively. In particular, the membranes of PCL / OG20% Ox and PCL / rOG are the substrate with the greatest astroglial differentiation capacity, as reflected in the number of cellular extensions and the expression level of glial acid fibrillar protein.
Line 3. Genetic and epigenetic factors that regulate gene expression during vertebrate embryogenesis.
The main interest of this line, developed in the laboratory directed by Dr. Álvaro Rada-Iglesis, is to discover the genetic and epigenetic factors that control the deployment of gene expression programs during vertebrate embryogenesis. With this objective, we are using a multidisciplinary approach that combines in vitro and in vivo models with biochemical, genomic and genetic engineering tools. Inspired by our work on vertebrate embryogenesis, we are applying similar experimental approaches to discover the molecular basis of human congenital diseases. More specifically, we are investigating how genetic variants and genomic rearrangements can lead to human disease through the alteration of gene regulatory scenarios (“landscapes”).
Our main future objective is to investigate the pathological consequences of the alteration of transcription regulatory networks.
Line 4. Study of the perivascular colonization of brain metastases in the mouse.
A collaboration has been initiated with the Brain Metastasis Group (CNIO. Madrid), led by Dr. Manuel Valiente, to analyze the cellular basis of perivascular colonization of brain metastases from cells from human lung carcinomas in the cerebral cortex mouse. It is intended to study the differentiation patterns and behavior of tumor cells, including proliferation capacity, in the perivascular niche. Particular attention will be given to the interactions of tumor cells with the endothelium and pericytes, in the vascular pole, and with astrocytes and neuropil (dendrites, axons and synaptic regions) in the neural pole of metastases. Preliminary results at the ultrastructural level suggest a great capacity for the integration of tumor cells in the perivascular niche, without inducing substantial changes in the structural microenvironment of the surrounding nerve tissue. The analysis of the cellular and molecular bases that regulate the interaction between tumor tissue and nerve tissue, a determining factor in the progression of metastases, is one of the fundamental objectives of this line of research.
Figura 2. Motoneurona espinal de un modelo murino de atrofia muscular espinal (SMA) que muestra la alteración en el procesamiento nuclear de RNAs con retención nuclear de mRNAs poliadenilados que concentran la proteína de unión al RNA Sam62