Perilipin is present in islets of Langerhans and protects against lipotoxicity when overexpressed in the beta-cell line INS-1.

Summary, in English

Lipids have been shown to play a dual role in pancreatic beta-cells - a lipid-derived signal appears to be necessary for glucose-stimulated insulin secretion, whereas lipid accumulation causes impaired insulin secretion and apoptosis. The ability of the protein perilipin to regulate lipolysis prompted an investigation of the presence of perilipin in the islets of Langerhans. In this study evidence is presented for perilipin expression in rat, mouse and human islets of Langerhans as well as in the rat clonal beta-cell line INS-1. In rat and mouse islets, perilipin was verified to be present in beta-cells. In order to examine if the development of lipotoxicity could be prevented by manipulating the conditions for lipid storage in the beta-cell, INS-1 cells with adenoviral-mediated overexpression of perilipin were exposed to lipotoxic conditions for 72 hours. In cells exposed to palmitate, perilipin overexpression caused increased accumulation of triacylglycerols and decreased lipolysis compared to control cells. Whereas glucose-stimulated insulin secretion was retained following palmitate exposure in cells overexpressing perilipin, it was completely abolished in control beta-cells. Thus, overexpression of perilipin appears to confer protection against the development of beta-cell dysfunction following prolonged exposure to palmitate by promoting lipid storage and limiting lipolysis.