过表达ω-3多不饱和脂肪酸脱氢酶基因fat-1保护小鼠胚胎成纤维细胞避免凋亡

由于膳食原因，人体摄入ω-6PUFAs/ω-3PUFAs比例过高，脂类代谢严重失衡.鉴于ω-3PUFAs获取困难而且人体无催化ω-6PUFAs向ω-3PUFAs转化的ω-3多不饱和脂肪酸脱氢酶，本研究体外扩增来源于秀丽线虫(Caenorhabditis elegans)的ω-3多不饱和脂肪酸脱氢酶基因（fat-l）cDNA，构建了真核表达载体pEGFPC1-fat-1，将该基因转染入小鼠胚胎成纤维细胞；激发荧光与RT-PCR方法检测转染pEGFPC1-fat-1细胞表达该基因，气相色谱分析显示该转染细胞中ω-6PUFAs/ω-3PUFAs的比例降低；细胞抑制率实验显示转染细胞的MTT吸光值升高（P <0.05）；双染法流式细胞仪分析转染细胞凋亡降低，结果表明fat-1基因即使在高浓度ω-6PUFAs的细胞毒作用下，依然能够发挥将ω-6PUFAs脱氢转化为与ω-3PUFAs的生理功能，抑制3T3细胞凋亡，促进细胞生长增殖，实现了较强的细胞保护功能.

Overexpression of ω-3 Fatty Acid Dehydrogenase Gene Protects Mouse Embryonic Fibrocytes from ω-6 PUFAs-induced Apoptosis

ω-3 polyunsaturated fatty acids (ω-3PUFAs) are important for the normal function of mammals. However, it is difficult to gain ω-3PUFAs in human body and there is no ω-3PUFAs dehydrogenase in vivo to catalyze ω-6PUFAs into ω-3PUFAs. But the expressed product of fat-1 gene from Caenorhabditis elegan is ω-3 PUFAs dehydrogenase. Hence, to express fat-1 gene in mouse embryonic fibrocyte is the aim of this study. First, the eukaryotic expression vector pEGFPC1-fat-1, containing fat-1 gene cDNA was constructed and transfected into mouse embryonic fibrocyte. Then the expression level was detected by RT-PCR and Laser Scanning Confocal Microscope, the change of cellular ω-6PUFAs /ω-3PUFAs ratio was examined by gas chromatography, the inhibiting rate of cells proliferation was observed by MTT method, and cell apoptosis was evaluated by flow cytometry. Results showed that the cells proliferation rate was higher and cells apoptosis magnitude was lower than those in the control cells. In conclusion, fat-1 gene could significantly decrease the ratio of cellular ω-6PUFAs /ω-3PUFAs and inhibit apoptosis of the 3T3 cell. It shows strong cell-protective effects on mouse embryonic fibrocyte.