The long-acting amylin/calcitonin receptor agonist ZP5461 suppresses food intake and body weight in male rats

Abstract

The peptide hormone amylin reduces food intake and body weight, and is an attractive candidate target for novel pharmacotherapies to treat obesity. However, the short half-life of native amylin and amylin analogs like pramlintide limits these compounds' potential utility in promoting sustained negative energy balance. Here, we evaluate the ability of the novel long-acting amylin/calcitonin receptor agonist ZP5461 to reduce feeding and body weight in rats, and also test the role of calcitonin receptors (CTRs) in the dorsal vagal complex (DVC) of the hindbrain in the energy balance effects of chronic ZP5461 administration. Acute dose-response studies indicate that systemic ZP5461 (0.5-3 nmol/kg) robustly suppresses energy intake and body weight gain in chow- and high-fat diet (HFD)-fed rats. When HFD-fed rats received chronic systemic administration of ZP5461 (1-2 nmol/kg), the compound initially produced reductions in energy intake and weight gain, but failed to produce sustained suppression of intake and body weight. Using virally-mediated knockdown of DVC CTRs, the ability of chronic systemic ZP5461 to promote early reductions in intake and body weight gain was determined to be mediated in part by activation of DVC CTRs, implicating the DVC as a central site of action for ZP5461. Future studies should address other dosing regimens of ZP5461 to determine whether an alternative dose/frequency of administration would produce more sustained body weight suppression.

Development of High Affinity Calcitonin Analog Fragments Targeting Extracellular Domains of Calcitonin Family Receptors

“…Mass spectrometry was performed at Genscript to confirm the molecular weight of the synthesized peptides. Fluorescein isothiocyanate (FITC)-labeled sCT (22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32), FITC-labeled AC413 (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25), and FITC-labeled AC413(6-25) with Y25P mutation were used as peptide probes for peptide binding assay. The extinction coefficient of FITC (63,000 M −1 •cm −1 at 495 nm, pH 7.0) was used to determine the concentration of the FITC-labeled peptide probes.…”

“…Background (reaction buffer only) was subtracted for anisotropy calculation. For the SpectraiD5, G factor (0.38 for FITC-sCT(22-32) and 0.41 for FITC-AC413 (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25) and FITC-AC413(6-25) Y25P) was used to correct the instrumental bias for anisotropy calculation. The polarization (mP) of the FITC-peptide probes only (No receptor ECD) was set close to 50 mP.…”

“…A rat amylin analog pramlintide was developed and is available in clinics to treat diabetes as co-therapy with insulin [8]. In addition, lots of effort has been focused on developing next-generation peptide drugs targeting AMY receptors as exemplified with dual amylin calcitonin receptor agonists (DACRA) and long-acting amylin/calcitonin receptor agonists [9][10][11][12][13].…”

THERAPY OF ENDOCRINE DISEASE: Amylin and calcitonin – physiology and pharmacology

“…This finding has been translated into the development of pramlintide, an amylin analogue approved by the Food and Drug Administration (FDA) in 2005 for the treatment of postprandial hyperglycaemia as an adjunct to meal-time insulin in individuals with type 1 diabetes or individuals with type 2 diabetes using mealtime insulin (14). Since the approval of pramlintide, no other amylin analogue has gained authority approval; however, several pharmaceutical companies are currently developing amylin-based therapies for obesity and type 2 diabetes (15,16,17). Calcitonin is a peptide hormone derived from thyroid C cells which is primarily known for finetuning calcium homeostasis, but it may also have glucometabolic effects (18).…”

“…Amylin and calcitonin are part of a peptide superfamily, consisting of hormones interacting with receptors based on the calcitonin receptor (CTR) or the calcitonin receptor-like receptor (CLR) (19). Because of the common structure of amylin and calcitonin receptors, dual amylin and calcitonin receptor agonists have emerged as possible therapies for obesity and type 2 diabetes in preclinical trials (15,17,20,21,22) and some are currently being pursued in clinical trials (16,23,24). These recent advances highlight the relevance of exploring the effects of amylin and calcitonin in the context of type 2 diabetes and other metabolic diseases.…”