GS-9620 inhibits enterovirus 71 replication mainly through the NF-κB and PI3K-AKT signaling pathways.

Human enterovirus 71 (EV71) is the second most common cause of hand, foot, and mouth disease (HFMD), which can occur as a severe epidemic especially among children under 5-years old. New and improved treatment strategies to control EV71 infection are therefore urgently required. The heterocyclic compound GS-9620, a potent and selective agonist of Toll-like receptor 7 (TLR7), has been reported to activate plasmacytoid dendritic cells (pDCs), and suppress HBV as well as HIV replication. In this study, we indicated that GS-9620 also could inhibit EV71 replication in the mouse model of EV71 infection. With three-days treatment after EV71 infection, the levels of proinflammatory cytokines/chemokines, like IFN-α, IFN-γ and MCP-1, were sharply reduced in serum compared to those without treatment. Furthermore, GS-9620 activated TLR7 in the limb muscle cells, which stimulated the NF-κB and PI3K/AKT signaling pathways. When NF-κB or PI3K/AKT inhibitors were used, the antiviral effect of the GS-9620 was impacted. Overall, our data implied GS-9620 probably activates NF-κB and PI3K/AKT signaling pathways to clear the virus.

Design, synthesis and biological evaluation of PEGylated Xenopus glucagon-like peptide-1 derivatives as long-acting hypoglycemic agents.

In order to develop novel long-acting GLP-1 derivatives, a peptide hybrid (1a) from human GLP-1 and Xenopus GLP-1 discovered in our previous research was selected as the lead compound. Exendin-4 inspired modification resulted in peptide 1b with enhanced glucose-lowering activity. Cysteine mutated 1b derivatives with reserved bioactivity were further site-specifically connected with mPEG2000-MAL to provide conjugates 3a-h, among which 3d and 3e were found to have significantly improved hypoglycemic activity and insulinotropic ability than GLP-1. The hypoglycemic durations of 3d and 3e were remarkably prolonged to ∼20 h in type 2 diabetic db/db mice, compared with the 5.3 h of exendin-4 in the same test. Finally, chronic in vivo studies revealed that a once-daily treatment of 3d or 3e for five weeks resulted in recovered glucose-controlling ability of type 2 diabetic db/db mice, along with other benefits, such as reduced body weight gains, food intake amounts and HbA1c values. Collectively, our results suggest 3d and 3e as potential long-acting glucose-lowering agents for treating type 2 diabetes.