Tau RNA reprogramming by trans-splicing

SONIA ESPINDOLA; ELENA AVALE

Huerta Grande, Cordoba

Congreso; XXVIII Congreso Anual de la Sociedad Argentina de Investigación en Neurociencia.; 2013

Sociedad Argentina de Investigacion en Neurociencias

The microtubule-associated protein Tau is predominantly expressed in neurons where it promotes microtubule polymerization and stabilization. Exclusion or inclusion of exon 10 (E10) by alternative splicing gives rise to Tau isoforms with either three (3R) or four (4R) microtubule-binding repeats. In the normal adult human brain the ratio 4R/3R is about 1. Recent genetic evidence demonstrated that some neurodegenerative diseases characterized by the intracellular aggregation of tau (tauopathies) are associated with aberrant splicing of E10, which alters the normal balance between 4R/3R isoforms. Our goal is to modulate the inclusion of E10 in tau mRNA using a strategy that creates a chimaeric RNA through a trans-splicing reaction between the endogenous mRNA and an exogenously delivered RNA molecule (the pre-trans-splicing motif: PTM). We have used lentiviral vectors (LVs) to achieve efficient delivery and long-term expression of Tau-PTMs into differentiated neurons. We constructed LVs carrying PTMs that were tested in human neuroblastoma cells, mouse cultured primary neurons and into the mouse brain. Trans-spliced RNA products and efficient isoform conversion from 3R to 4R Tau were detected by RT-PCR. Together, our results provide a proof of concept for the use of LVs to reprogram Tau RNA in vivo and set the grounds to use RNA trans-splicing to achieve phenotypic recovery in models of tauopathy and other disorders linked to aberrant RNA processing.