1612-P: Energetic Contributions of GLP1 and GCGR Activity in GLP1/GIP/GCGR Triagonism

Abstract

Glucagon has been implicated as a key diabetogenic factor. However, agonists that couple the lipolytic and thermogenic properties of Glucagon Receptor (GCGR) activity with the antidiabetic actions of incretins (GLP1, GIP), lack hyperglycemic side effects associated with GCGR activity. GCGR agonism stimulates energy expenditure (EE) that contributes to weight loss. Interestingly, we also identified that the anti-obesity effects of GCGR agonism persisted for 50d after treatment cessation. Thus, we hypothesized that GCGR activity paired with incretin action (GGG) will result in increased EE during treatment and prolonged weight loss after cessation. Diet-induced obese mice were treated for 14d with vehicle, GGG, or single receptor agonism via IUB288 (GCGR), Semagutide (Sema;GLP1R), or GIP-FA 085 (GIPR). Indirect calorimetry was conducted for d 2-4 of treatment and d 16-18 after cessation. Congruent with our prior studies, IUB288 increased EE compared to vehicle controls. Conversely, Sema-treated mice displayed decreased EE (d 2 and 3) while EE following GIP treatment was similar to vehicle controls. Intriguingly, GGG reduced EE on d 2, had similar EE to vehicle controls on d 3, with a trend towards increased EE on d 4, suggesting GGG treatment stimulates characteristics of both GLP1 and GCGR activity. Nutrient utilization, measured via Respiratory Quotient (RQ), was reduced during the light period with IUB288 treatment. GIP, Sema, and GGG reduced RQ, regardless of time of day. Interestingly, GGG regulation of RQ appeared most like Sema. After treatment cessation, Sema mice gained significantly more weight than IUB288 or GGG mice, despite similar food intake during rebound. Surprisingly, EE was not elevated in mice that formerly received IUB288 or GGG, suggesting another mechanism may be driving this effect. RQ was similar in all groups, except IUB288 mice, which exhibited increased RQ across the day. These data suggest that GGG exhibits effects of both GLP1R and GCGR agonism with respect to EE and RQ. Disclosure S.Nason: None. J.Antipenko: None. K.M.Habegger: Consultant; Glyscend Inc., Research Support; Eli Lilly and Company, Novo Nordisk, Glyscend Inc., Stock/Shareholder; Glyscend Inc. Funding Eli Lilly and Company