The novel chimeric multi-agonist peptide (GEP44) reduces energy intake and body weight in male and female diet-induced obese mice in a glucagon-like peptide-1 receptor-dependent manner

• Published in: Frontiers in endocrinology (Lausanne) Vol. 15; p. 1432928
• Main Authors: Blevins, James E, Honeycutt, Mackenzie K, Slattery, Jared D, Goldberg, Matvey, Rambousek, June R, Tsui, Edison, Dodson, Andrew D, Shelton, Kyra A, Salemeh, Therese S, Elfers, Clinton T, Chichura, Kylie S, Ashlaw, Emily F, Zraika, Sakeneh, Doyle, Robert P, Roth, Christian L
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 22.07.2024
• Subjects: Animals; Body Weight - drug effects; Diet, High-Fat - adverse effects; Endocrinology; Energy Intake - drug effects; Female; GLP-1; Glucagon-Like Peptide-1 Receptor - agonists; Glucagon-Like Peptide-1 Receptor - metabolism; IBAT; IWAT; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Obese; multi-agonist; obesity; Obesity - drug therapy; Obesity - metabolism; PYY; PYY; GLP-1; IWAT; multi-agonist; IBAT; obesity
• ISSN: 1664-2392; 1664-2392
• DOI: 10.3389/fendo.2024.1432928

We recently reported that a novel chimeric peptide (GEP44) targeting both the glucagon-like peptide-1 receptor (GLP-1R) and neuropeptide Y1- and Y2 receptor (Y1R and Y2R) reduced energy intake and body weight (BW) in diet-induced obese (DIO) rats. We hypothesized that GEP44 reduces energy intake and BW primarily through a GLP-1R dependent mechanism. To test this hypothesis, GLP-1R mice and GLP-1R null (GLP-1R ) mice were fed a high fat diet for 4 months to elicit diet-induced obesity prior to undergoing a sequential 3-day vehicle period, 3-day drug treatment (5, 10, 20 or 50 nmol/kg; GEP44 vs the selective GLP-1R agonist, exendin-4) and a 3-day washout. Energy intake, BW, core temperature and activity were measured daily. GEP44 (10, 20 and 50 nmol/kg) reduced BW after 3-day treatment in DIO male GLP-1R mice by -1.5 ± 0.6, -1.3 ± 0.4 and -1.9 ± 0.4 grams, respectively ( <0.05), with similar effects being observed in female GLP-1R mice. These effects were absent in male and female DIO GLP-1R mice suggesting that GLP-1R signaling contributes to GEP44-elicited reduction of BW. Further, GEP44 decreased energy intake in both male and female DIO GLP-1R mice, but GEP44 appeared to produce more consistent effects across multiple doses in males. In GLP-1R mice, the effects of GEP44 on energy intake were only observed in males and not females, suggesting that GEP44 may reduce energy intake, in part, through a GLP-1R independent mechanism in males. In addition, GEP44 reduced core temperature and activity in both male and female GLP-1R mice suggesting that it may also reduce energy expenditure. Lastly, we show that GEP44 reduced fasting blood glucose in DIO male and female mice through GLP-1R. Together, these findings support the hypothesis that the chimeric peptide, GEP44, reduces energy intake, BW, core temperature, and glucose levels in male and female DIO mice primarily through a GLP-1R dependent mechanism.