Search for orphan drugs using bioinformatics tool and in vitro validation

More than seven thousand diseases with a very low prevalence in the population are defined as rare. Only in a few cases is available a treatment option, not always successful. The leading topic of this PhD project is the identification of drugs as therapeutics for rare diseases triggered by protein instability. Small molecules that stabilize the protein were under investigation by using several approaches from bioinformatics searching and design to in vitro validation. The objects of study were three rare disorders in which genetic mutations lead to misfolded and unstable proteins: i) Fabry disease (FD) ii) Transthyretin amyloidosis (ATTR) and iii) PMM2- congenital disorder of glycosylation (PMM2- CDG). I benefited from the experience of my tutor Dr. Andreotti in the development of pharmacological chaperones (PCs) for orphan diseases, including FD and PMM2- CDG. Furthermore, the collaboration with organic chemists gave me the opportunity to assay de novo synthesis molecules as ATTR inhibitors extending my research to a different disease. i)Fabry disease is caused by mutation in the GLA gene which encode the alpha- galactosidase A (AGAL), resulting in the deleterious accumulation of globotriaosylceramide. Two approved treatments, enzyme replacement and PC therapy, exhibit severe limitations that prompt the search for new therapeutic options. ii)Transthyretin (TTR) is a tetrameric protein leading to human amyloidosis when it is unstable due to mutations or aging. A promising therapeutic strategy concerns the use of small molecules to stabilize TTR and prevent the deposition of amyloid fibrils, but an effective and safe drug is not available. iii)The most common congenital disorder of glycosylation occurs when phosphomannomutase-2 (PMM2) is mutated. The loss of stability and functionality of the PMM2 enzyme damages the N-glycosylation process and leads to a heterogeneous clinical phenotype ranging from mild to very severe. Unfortunately, there is still no cure for these patients. However, a couple of potential drugs are in clinical trials (Acetazolamide, Epalrestat). The absence of biomarkers or ideal cellular models hampers the achievement of this goal. In this context, I also contributed to the characterization of a yeast model, already successfully applied for drug screening and possibly useful for better deciphering the molecular basis of PMM2- CDG.