α-亚麻酸抑制高脂诱导的脂肪细胞氧化应激和促炎因子的释放

ALA inhibits oxidative stress and the generation of proinflammatory cytokines induced by free fatty acids in adipocyte

目的通过给予3T3-L1脂肪细胞高脂处理,探讨α-亚麻酸(α-linolenic acid,ALA)抑制脂肪细胞促炎因子释放和氧化应激的作用及其机制。方法给予ALA预处理的成熟3T3-L1脂肪细胞棕榈酸酯(palmitate)以及20 mmol/L原卟啉锡(SnPP)处理,检测炎症因子TNF-α和IL-6水平;HO-1、SOD、CAT以及GCLC表达水平以及NF-κB核转位和细胞中ROS水平。结果ALA可剂量依赖性地抑制高脂诱导的脂肪细胞中促炎因子TNF-α、IL-6的产生(P<0.01);ALA显著增加了高脂处理的脂肪细胞中抗氧化相关因子HO-1、CAT、SOD、GCLC的表达,减少细胞中ROS生成,抑制NF-κB的活化(P<0.01);HO-1抑制剂可阻断上述ALA对脂肪细胞的抗炎和抗氧化作用。结论 ALA可以显著抑制高脂诱导的脂肪细胞促炎因子的分泌以及氧化应激反应,其机制可能与促进HO-1表达、抑制ROS产生从而抑制NF-kB介导的炎症反应有关。

This study was designed to investigate the inhibition of α-linolenic acid（ALA） on oxidative stress and the generation of proinflammatory cytokines induced by free fatty acids in adipocytes as well as its mechanism.In one group, 3 T3-L1 adipocytes were induced for differentiation for 7 days, and then pretreated with ALA（10, 50,100 mmol/L） for 18 hours. After that, they were stimulated with 250 mmol/L palmitate for 24 hours. In another group,pre-adipocytes were treated with SnPP when they were induced for differentiation. Cytokines TNF-α and IL-6 levels in supernatant was measured by ELISA; the protein levels of HO-1 and NF-κB nuclear translocation were detected by Western blotting; while the gene expression of HO-1, SOD, CAT as well as GCLC were measured by qPCR. ROS level was tested by a specific Amplex red ROS detection assay kit from Thermo Fisher Co. Data showed that palmitate caused a significant increase of cytokines TNF-α and IL-6 in mature 3 T3-L1 adipocytes, and ALA treatment suppressed this effect in a dose-dependent manner. Furthermore, ALA promoted the gene expression levels of HO-1, CAT, SOD and GCLC, reduced the ROS production, as well as inhibited the nuclear translocation of NF-κB. However, these merits of ALA were blocked by SnPP, a specific inhibitor of HO-1. Potentially, by promoting HO-1 expression and inhibiting NF-κ B activation, ALA could improve the oxidative stress and inhibit the production of proinflammatory cytokines induced by free fatty acids in adipocytes with a dose dependent way.