Laboratory of Mass Spectrometry-APLIPID, Faculté de Médecine Pierre et Marie Curie, ER7-UPMC, Paris, France.
Prostaglandins Leukot Essent Fatty Acids. 2013 Feb;88(2):149-54. doi: 10.1016/j.plefa.2012.12.001. Epub 2013 Jan 10.
We assessed - by a lipidomic approach - the differential incorporation of EPA and DHA into hepatic lipids, after prolonged feeding of rats with fish oil. We also evaluated their effect on lipogenesis and its related enzymes. Rats were administered 100 mg/kg/d fish oil, by oral gavage, for 30 days. The fatty acid profile of total liver lipids was determined by gas-liquid chromatography coupled to mass spectrometry. Individual phospholipid classes and their molecular species were quantified by ESI-MS/MS. Omega 3 fatty acids readily incorporated into hepatic phospholipids, decreased stearoyl-CoA desaturase 16, stearoyl-CoA desaturase, delta 6 desaturase, and delta 5 desaturase activities (calculated as product/substrate ratio) and decreased the "lipogenesis index", i.e., the proportion of fatty acids endogenously synthesized in the liver and not provided with the diet. Our results show that long-chain omega 3 fatty acids selectively incorporate into hepatic phospholipids, inhibit de novo lipogenesis and change the hepatic fatty acid profile via reduced desaturases' activity in the non-steatotic liver. In addition to corroborating advice to consume adequate amounts of omega 3 fatty acids for overall health, these data contribute mechanistic insights to the clinical observations that provision of omega 3 fatty acids decreases hepatic fat and ameliorates NAFLD prognosis.
我们通过脂质组学方法评估了长期给大鼠喂食鱼油后，EPA 和 DHA 进入肝脂质的差异情况。我们还评估了它们对脂肪生成及其相关酶的影响。大鼠通过口服灌胃每天给予 100mg/kg 的鱼油，共 30 天。通过气相色谱-质谱联用仪测定总肝脂质的脂肪酸谱。通过电喷雾质谱/质谱（ESI-MS/MS）定量测定各磷脂类及其分子种类。ω-3 脂肪酸很容易掺入肝磷脂中，降低硬脂酰辅酶 A 去饱和酶 16、硬脂酰辅酶 A 去饱和酶、Δ6 去饱和酶和 Δ5 去饱和酶的活性（以产物/底物比计算），并降低“脂肪生成指数”，即肝脏内源性合成的脂肪酸比例，而不是饮食提供的脂肪酸比例。我们的结果表明，长链 ω-3 脂肪酸选择性地掺入肝磷脂中，通过减少非脂肪性肝病肝脏中去饱和酶的活性，抑制从头脂肪生成并改变肝脂肪酸谱。除了证实摄入足够的 ω-3 脂肪酸对整体健康有益的建议外，这些数据还为临床观察提供了机制上的见解，即提供 ω-3 脂肪酸可减少肝脂肪并改善非酒精性脂肪性肝病的预后。
