OMEGA-3 POLYUNSATURATED FATTY ACIDS AFFECT LEPTIN RECEPTOR GENE EXPRESSION IN PITUITARY GH4C1 CELL LINE

Leptin (Ob) and Ob receptor (Ob-Rb) genes are expressed in human and rodent anterior pituitary, and an autocrine/paracrine loop in the production and regulation of Ob and Ob-Rb in this tissue has been suggested. As brain membranes contain large amounts of polyunsaturated fatty acids (PUFAs), and PUFA may affect the levels of leptin as well as the receptor's environment, a possible regulatory role of exogenous PUFA on Ob and Ob-Rb expression in pituitary cell lines was investigated. GH4C1 cells were incubated with arachidonic (ARA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids and fatty acid incorporation, viability, and gene expression were measured. The results showed that although fatty acids were incorporated in GH4C1 cells at a minimum level, positively affected cell viability without differences, among the different fatty acids. On the contrary, ARA, EPA and DHA showed different effects on Ob-Rb gene regulation that was upregulated by EPA, downregulated by DHA and not affected by ARA. The effects of leptin co-incubation are also reported and discussed. PRACTICAL APPLICATIONS Data from this paper consolidate the observations regarding the role of n-3 polyunsaturated fatty acid in gene expression regulation, and thus they could support the recommendation to enrich diet with fish or fish oil with high PUFA content.