PGLP-1, a novel long-acting dual-function GLP-1 analog, ameliorates streptozotocin-induced hyperglycemia and inhibits body weight loss

It is well known that glucagon-like peptide 1 (GLP-1) has antidiabetic action. It has 2 distinct functions, an insulinotropic effect dependent on GLP-1 receptor (GLP-1R) and an insulinomimetic effect independent of GLP-1R. However, use of GLP-1 in vivo is limited by its short half-life. Therefore, our lab designed PGLP-1, a novel 2-function candidate peptide as a potential substitute. Using a streptozotocin-induced hyperglycemic mouse model, we demonstrated in vitro and in vivo that PGLP-1 had insulinotropic actions dependent on GLP-1R and insulinomimetic functions independent of GLP-1R. PGLP-1 treatment increased islet β-cell mass, plasma insulin, and C-peptide levels and Ki-67-immunoreactive β-cell numbers, verifying that PGLP-1 can work as a short GLP-1R agonist, similar to commercially available exendin-4. Additionally, PGLP-1 improved insulin sensitivity, inhibited gluconeogenesis by increasing expression of AMPK and receptor subfamily 0, group B, member 2 (SHP), and inhibited body weight loss by inh...