Studies on PRPF40B/MECP2 crosstalk in Rett syndrome

This project has been funded thanks to the Joint Call Fondazione Cariplo and Fondazione Telethon 2022 

RTT is a progressive neurological disorder affecting mainly girls, with a frequency of about 1:10,000 births. To date, there is no cure. The causative factor for more than 95% of patients is a mutated MeCP2 gene. MeCP2 encodes a multifunctional protein implicated in gene transcription, chromatin organization and RNA splicing. MeCP2 functions and the molecular mechanisms that mediate RTT neuropathology are still partially unknown. In this frame, a better understanding of MeCP2 activities, particularly its role in splicing regulation, is extremely relevant. In the nervous system, the process of maturation of precursor mRNAs is regulated by AS mechanisms that rearrange the pattern of coding regions into alternative mature mRNAs that translate to different proteins. AS is a finely regulated process  that represents a post-transcriptional mechanism by which cells expand their genetic information to accomplish highly diversified and complex functions. Defects in splicing underlie many human neurological diseases and might contribute to the pathophysiology of RTT. PRPF40B is an AS regulator shown to bind to MeCP2, binding abrogated by MeCP2 C-terminal truncations. The aim of this project is the characterization of the PRPF40B-MeCP2 interaction in neuronal cells and the study of its functional significance in the context of RTT. By high-throughput RNAseq, we will analyze the AS profile of iPSC-derived neurons from a patient with a MeCP2 C-terminal deletion abrogating the PRPF40B binding domain. Bioinformatic analysis of differentially spliced genes will be performed to infer genes and pathways relevant for the disease and potential targets for the development of new therapies.