ABSTRACT
Alternative splicing is a key mechanism for neuronal gene regulation, and is grossly altered in mouse brain reward regions following investigator-administered cocaine. It is well established that cocaine epigenetically regulates transcription, yet mechanism(s) by which cocaine-induced epigenetic modifications regulate alternative splicing is largely unexplored. Our group and others have previously identified the histone modification, H3K36me3, as a putative splicing regulator. However, it has not yet been possible to establish the direct causal relevance of this modification to alternative splicing in brain or any other context. We found that mouse cocaine self-administration caused widespread alternative splicing, concomitant with enrichment of H3K36me3 at splice junctions. Differentially spliced genes were enriched in the motif for splice factor, Srsf11, which was both differentially spliced and enriched in H3K36me3. Epigenetic editing led us to conclude that H3K36me3 functions directly in alternative splicing of Srsf11, and that Set2 mediated H3K36me3 bidirectionally regulates cocaine intake.
Footnotes
This version includes new data that strengthens evidence of the role of Set2 in bidirectional regulation of cocaine reward behavior. These data are (1) the attenuation of cocaine place preference following intra-NAc administration of a Set2 inhibitor and (2) positive linear correlation between H3K36me3 enrichment and cocaine conditioned place preference and (3) positive linear correlation between NAc expression of Srsf11 alternative isoform and infusions during cocaine self-administration.