Research projects

Systemic sclerosis (SSc), systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are systemic autoimmune diseases of complex aetiology, in which the interaction between environmental and genetic factors is essential for the onset of the disease. These diseases share not only many clinical traits, but also part of their genetic component, and these regions of the genome are known to be common genes giving susceptibility to autoimmune diseases. The degree to which two diseases share their genetic components varies from one case to another, and are very similar in SSc and SLE; RA is less similar to these two. The proposal presented here centres on characterising and investigating the shared elements of epigenetic deregulation of these diseases. More specifically: a) obtaining and validating the DNA methylation profiles of the different cell types associated with the pathology of SSc, SLE and RA, and b) the integration of the methylation data with GWAS data obtained previously by members of the research team and the study of the possible relationship between the genotype and methyltype, as well as the points in common shared by the three diseases. In this first year, the project centred on the characterisation of the elements involved in the epigenetic deregulation of RA, and the information on alterations in the level of methylation of DNA has been integrated with data on the deregulation of microRNAs and expression, which may be controlled by changes in the methylation and deregulation of microRNAs. This first study has made it possible to obtain a series of epigenetic deregulation markers, and the study undertaken is the first integrated approach to the study of deregulation of genetic expression in RA. This study was published in the Journal of Autoimmunity. An initial comparative analysis with SLE data shows that both diseases share a small number of epigenetic deregulation targets.