Identifying links between cardiovascular disease and insomnia by modeling genes from a pleiotropic locus.

Insomnia symptoms double the risk of cardiovascular disease (CVD), yet shared genetic pathways remain unclear. Genome-wide association studies identified a genetic locus (near ATP5G1, UBE2Z, SNF8, IGF2BP1 and GIP) linked to insomnia and CVD. We used Drosophila models to perform tissue-specific RNA interference knockdowns of four conserved orthologs (ATPsynC, lsn, Bruce and Imp) in neurons and the heart. Neuronal-specific knockdown of ATPsynC, Imp and lsn impaired sleep quantity and quality. In contrast, cardiac knockdown of ATPsynC and lsn reduced cardiac function and lifespan, with lsn knockdown also causing cardiac dilation and myofibrillar disorganization. Cross-tissue effects were evident: neuronal Imp knockdown compromised cardiac function, whereas cardiac ATPsynC and lsn knockdown increased sleep fragmentation and inflammation (marked by Upd3 elevation in the heart or head). Overexpression of Upd3 in neurons impaired cardiac function, and its overexpression in the heart disrupted sleep. Our findings reveal conserved genes mediating tissue-specific and cross-tissue interactions between sleep and cardiac function, providing novel insights into the genetic mechanisms linking insomnia and CVD through inflammation.