Setmelanotide (RM-493)

Setmelanotide (RM-493, BIM-22493, CAM 4072) is a cyclic peptide full agonist of melanocortin-4 receptor (MC4R) with an EC50 of 0.27 nM and a Ki of 2.1 nM.

Setmelanotide decreases TNF-α/IFN-γ-induced chemokine expression in astrocytes and increases IL-6 and IL-11 mRNA and protein secretion via MC4R. Setmelanotide Induces CREB phosphorylation in astrocytes and setmelanotide treated astrocytes secrete factors that are able to modulate macrophage polarization into an anti-inflammatory phenotype.^[2]

Cells were treated with 0.001–10 μM setmelanotide for 1 h and thereafter with TNF-α and IFN-γ for 4 h. For blocking experiments, 10 μM SHU9119 (26) was added 30 min before addition of setmelanotide during 4 h. Astrocytes stimulate with setmelanotide and or SHU9119 (10 μM) for 4 h, replace the medium with macrophage culture medium and add the medium to the macrophages 24 h thereafter. From the medium, 100 μL is collected in Eppendorf tubes and stored at −80°C for ELISA assays.

RM-493 and liraglutide co-treatment enhances weight loss in DIO mice and hypothalamic Glp-1r expression is higher in mice treated with the combination therapy after both acute and chronic treatment. Adjunctive administration of RM-493 and liraglutide improves glucose tolerance and insulin sensitivity, lowers fasting levels of glucose and insulin and decreases cholesterol levels beyond what can be achieved with the corresponding mono-therapies.^[3]