MULTI-SINEUP: A NOVEL RNA THERAPEUTIC APPROACH FOR 22Q11.2 MICRODELETION SYNDROME

SINEUPs are a class of natural and synthetic antisense long non-coding RNAs (lncRNAs) that selectively enhance the translation of partially overlapping sense mRNAs. Their modular architecture comprises two essential domains: a Binding Domain (BD), which confers target specificity through antisense base pairing, and an Effector Domain (ED), typically an inverted SINEB2 element, which promotes recruitment of the translational machinery. Through synthetic engineering, SINEUPs can be adapted to upregulate the protein expression of virtually any gene, making them particularly promising for the treatment of haploinsufficiency disorders, in which loss of a single allele results in reduced protein levels. Microdeletion syndromes such as 22q11.2 deletion syndrome pose a unique therapeutic challenge due to the simultaneous haploinsufficiency of multiple genes, leading to complex multi-organ and neuropsychiatric phenotypes.

In this study, we designed and synthesized the first multi-BD SINEUP capable of simultaneously targeting three key genes implicated in 22q11.2 deletion syndrome: TBX1, COMT, and DGCR8. The multi-target SINEUP significantly increased the protein levels of all three genes in vitro and in the mouse brain in vivo, and rescued cognitive deficits in the LgDel mouse model. Functional magnetic resonance imaging (fMRI) revealed restoration of disrupted connectivity between the prefrontal cortex and hippocampus, which significantly correlated with behavioral recovery. RNA-seq analyses suggested a molecular basis for these effects, supporting a cascade mechanism whereby DGCR8 restoration normalizes miRNA processing and facilitates circuit-level functional recovery. Collectively, these findings provide the first proof-of-concept for a multi-target SINEUP therapeutic strategy for complex genomic microdeletions.