Glucagon-like peptide-1 upregulates visfatin expression in 3T3-L1 adipocytes.

The incretin hormone glucagon-like peptide-1 (GLP-1) exerts important functions in controlling glucose homeostasis. Many studies have revealed molecular targets of GLP-1, but its influence on adipokines has not been determined. Visfatin, a recently discovered adipokine, has been shown to attenuate insulin resistance by binding to insulin receptor. Our study shows that GLP-1 induced secretion of visfatin into the culture medium of 3T3-L1 adipocytes due to increased visfatin mRNA expression. Furthermore, the effect of GLP-1 on visfatin was dose- and time-dependent. H89, a protein kinase A inhibitor, prevented the induction of visfatin expression by GLP-1. Moreover, inhibition of NF-κB by PDTC reduced the basal visfatin release while having no effect on the transcription regulation by GLP-1. In addition, GLP-1 alleviated the decrease of visfatin mRNA expression under endoplasmic reticulum stress induced by thapsigargin. Taken together, our study suggests that GLP-1 promotes the novel insulin-mimetic adipocytokine visfatin expression via the PKA pathway and might influence glucose metabolism. © Georg Thieme Verlag KG Stuttgart · New York.