Dottorato in BIOLOGIA CELLULARE E DELLO SVILUPPO

Titolo della tesi: Drug repositioning for multiple sclerosis: in silico and in vitro methods

The immune attack in multiple sclerosis (MS) triggers a cascade of events that damage myelin sheath and axons, disrupting nerve signal transmission. The main focus of regenerative therapies for MS is to promote neuron survival and induce the differentiation of oligodendrocyte progenitor cells (OPC) present within areas of demyelination into remyelinating oligodendrocytes. My thesis focuses on two different studies aimed at identifying oral drug candidates with potential central nervous system (CNS) regenerative activity using distinct approaches providing drug-target disease connection. The first study is part of an international project that aims to: i) develop a library of registered and abandoned drugs linked to neuroprotective and/or myelinating pathways by a bioinformatic platform; ii) provide evidence of drug activity in in vitro models of OPC and neurons; iii) unveil the protective and/or regenerative mode of action of the most promising compounds; iv) assess the pharmacological activity of hit compounds in in vivo efficacy studies using different rodent disease models. During the four years of the project, the library of computational selected drugs was tested in multiple rodent and human cell-based assays to find compounds able to induce oligodendrocyte differentiation and protect neurons from damage. Ranking and prioritization of drugs allowed for the selection of two hits with neuroprotective and promyelinating activity and pharmacokinetics favorable properties. Drug discovery methodologies were then applied to identify a new biological target shared by the two hits, increasing knowledge about their mode of action. Within this project, I was directly involved in drug screening for OPC survival and differentiation, and in the computational and cell-based experiments of drug-target interactions. The second study aims to exploit human genetic data of MS for prioritization of drug targets involved in oxidative stress (OS), which is one of the major driving component of CNS damage in MS disease progression. We first searched for genes and/or gene products regulated by genetic variants in MS and all proteins belonging to OS-related pathways. The overlap of these data sets allowed for the identification of 85 OS-related proteins (recorded as “targets”) regulated by functional MS variants that were prioritized through a score assignment. Query of public drug databases for the 21 top targets enabled the selection of 10 drugs either already approved or in clinical trials that bind to five MS molecular targets showing a favorable pharmacokinetic for repurposing in MS. In particular, I was directly involved in establishing the list of oxidative stress-related proteins and in drug searching and selection by means of four different databases. In addition, I actively participated in reviewing and editing the manuscript that is presented in section II of this thesis.