Targeting postsynaptic glutamate receptor scaffolding proteins PSD-95 and PICK1 for obesity treatment

Abstract: Human genome-wide association studies (GWAS) suggest a functional role for central glutamate receptor signaling and plasticity in body weight regulation. Here, we utilize UK Biobank GWAS summary statistics of body mass index (BMI) and body fat percentage (BF%) to identify genes encoding for proteins known to interact with postsynaptic AMPA and NMDA receptors. Loci in/near Discs Large MAGUK Scaffold Protein 4 (DLG4) and protein interacting with C kinase 1 (PICK1) reached genome-wide significance (P<5x10-8) for BF% and/or BMI. To further evaluate the functional role of PSD-95 (gene name: DLG4) and PICK1 in energy homeostasis, we used dimeric PDZ-domain-targeting peptides of PSD-95 and PICK1 to demonstrate that pharmacological inhibition of PSD-95 and PICK1 induces prolonged weight-lowering effects in obese mice. Collectively, these data demonstrate that the glutamate receptor scaffolding proteins, PICK1 and PSD-95, are genetically linked to obesity and that pharmacological targeting of their PDZ domains represents a promising new therapeutic avenue for sustained weight loss.