Transcriptional States Underlying Cagrilintide Signaling in the Dorsal Vagal Complex

Background: The long-acting amylin receptor agonist cagrilintide induces weight loss in part through activation of neuronal circuits in the brainstem dorsal vagal complex (DVC). Despite similar in vitro potencies, an in vivo species difference in weight loss is observed. We recently characterized calcitonin receptor (Calcr)-expressing neuronal populations in the mouse area postrema (AP) and nucleus of the solitary tract (NTS), which can sense amylin-related peptides. Here, we investigated whether additional DVC Calcr populations exist across species and how cagrilintide engages primary and secondary responders to induce long-term effects on energy balance. Methods: We applied single-nucleus RNA-sequencing (snRNA-seq) of diet-induced obese mice following either acute or subchronic treatment with cagrilintide. We integrated the mouse atlas with snRNAseq data from untreated rhesus macaques and rats. Finally, we ran bulk RNA-seq on cagrilintide-treated mice and rats. Results: Sequencing more than 200,000 DVC cells, we constructed an atlas comprising distinct cell populations with overall conserved transcriptional signatures across macaques, mice, and rats. Among these, five neuronal populations showed high expression of Calcr. Expectedly, cagrilintide enhanced expression of regulons controlled by primary response genes in AP Calcr neurons in mice. Interestingly, upon subchronic treatment, these regulons were no longer upregulated in mice, whereas the same regulons were upregulated in rats. In rats, we further identified prolactin releasing hormone (Prlh), a gene that, when overexpressed in mice, can abrogate obesity and is expressed dominantly in NTS Calcr neurons, was among the most differentially expressed genes. Conclusions: Together, our results suggest that cagrilintide treatment induces sustained activation of neurons in the rat DVC, including Prlhexpressing Calcr neurons, but not in the mouse DVC, and provide a comprehensive resource of species-specific and preserved cell populations in the DVC.