四个脂肪酸合成酶基因在哺乳动物细胞中的超表达提高长链多不饱和脂肪酸生物合成效率

发布时间：2018-10-21 14:25

【摘要】：DHA(22:6n-3)、EPA(20:5n-3)和ARA(20:4n-6)三种长链多不饱和脂肪酸在生物体内活性最强,它们在促进大脑发育和功能维持以及在预防和治疗心血管疾病、炎症、癌症等多种疾病方面有着重要作用。然而,尽管哺乳动物体内有完整的长链多不饱和脂肪酸合成酶系,但哺乳动物合成这些长链多不饱和脂肪酸的效率很低而主要依赖于食物获取。本研究应用转基因方法,将哺乳动物来源的Δ6和Δ5脂肪酸去饱和酶以及Δ6和Δ5脂肪酸延长酶这4种酶的编码基因构建成为一个多基因表达载体,然后转染哺乳动物细胞HEK293T,实现了4个目的基因的超表达,再通过气质联用(GC-MS)分析证实了DHA、EPA和ARA等长链多不饱和脂肪酸的合成效率及水平显著增加,DHA的水平更是提高了2.5倍。由此可见,哺乳动物具有某种抑制长链多不饱和脂肪酸高水平合成的机制,但通过Δ6和Δ5脂肪酸去饱和酶以及Δ6和Δ5脂肪酸延长酶的超表达,能够打破哺乳动物这种抑制机制,从而显著提高DHA、EPA、ARA等的合成水平。同时,本研究的思路也为在转基因动物中生产长链多不饱和脂肪酸提供了重要的启示。
[Abstract]:DHA (22:6n-3), EPA (20:5n-3) and ARA (20:4n-6) are the most active long chain polyunsaturated fatty acids in vivo. They play an important role in promoting brain development and functional maintenance and in preventing and treating cardiovascular diseases, inflammation, cancer and other diseases. However, although there are complete long chain polyunsaturated fatty acid synthase systems in mammals, the efficiency of the synthesis of these long chain polyunsaturated fatty acids in mammals is very low and is mainly dependent on food acquisition. In this study, the genes encoding 螖 6 and 螖 5 fatty acid desaturase and 螖 6 and 螖 5 fatty acid prolongation enzymes from mammalian origin were constructed into a multi-gene expression vector by transgenic method. Four target genes were overexpressed by transfection of mammalian HEK293T, and the synthesis efficiency and level of long chain polyunsaturated fatty acids such as DHA,EPA and ARA were significantly increased by GC-MS analysis, and the level of DHA was increased by 2.5 times. It can be seen that mammals have some mechanism to inhibit the high level synthesis of long chain polyunsaturated fatty acids, but this mechanism can be broken by the overexpression of 螖 6 and 螖 5 fatty acid desaturase and 螖 6 and 螖 5 fatty acid prolongation enzymes. Thus, the synthesis level of DHA,EPA,ARA et al was improved significantly. At the same time, the idea of this study also provides important inspiration for the production of long chain polyunsaturated fatty acids in transgenic animals.
【作者单位】：佳木斯大学基础医学院;
【基金】：国家自然科学基金(No.31000984) 黑龙江省教育厅科学技术研究项目(No.12511563)资助~~
【分类号】：R3416

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