Production of Functional γ-Linolenic Acid (GLA) by Expression of Fungal △2- and △6-Desaturase Genes in the Oleaginous Yeast Yarrowia lipolytica

摘要

γ-Linolenic acid (GLA; A6,9,12-18:3) is one of the n-6 polyunsaturated fatty acids (n-6 PUFAs) derived from linoleic acid (LA; A9,12-18:2), by the action of A6-desaturase.GLA has been demonstrated to exert different beneficial effects in a variety of cell cultures, animal models, and human studies. These effects include the reduction of inflammation-related diseases, such as rheumatoid arthritis and cystic fibrosis,through modulating of immune response [1-4], decrease in the development of hypertension [5], and progress of other chronic diseases like diabetes and cancer [6,7]. The mechanisms by which GLA exerts these biological functions have been attributed to its modulation of n-6 PUFA metabolism and eicosanoid synthesis. In mammals, Δ6-desaturation of LA to GLA is considered as a rate-limiting step of the n-6 PUFA metabolic pathway [8]. The reaction step is readily influenced by many physiological and pathological conditions [9]. Supplementation of GLA could bypass this step and resume the subsequent n-6 PUFA metabolism.