Grunfeld C, Dinarello C A, Feingold K R
Department of Medicine, University of California, San Francisco.
Metabolism. 1991 Sep;40(9):894-8. doi: 10.1016/0026-0495(91)90062-2.
Tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), and interferon alpha (IFN-alpha) stimulate hepatic lipogenesis in vivo. We now show that TNF-alpha, IL-1, and IFN-alpha stimulate lipogenesis as measured by the incorporation of 3H-glycerol into triglyceride in cultured HepG2 cells. Incubation of HepG2 cells for approximately 24 hours with TNF or IL-1 was required to see stimulation of lipogenesis, with this effect increasing over the next four days. TNF stimulated lipogenesis by 2.4-fold after 72 hours of incubation, while a 3.5-fold stimulation was seen with IL-1. The half maximal concentration for TNF stimulation of hepatic lipogenesis was 4 ng/mL, while that for IL-1 was 0.3 ng/mL. Cells treated with TNF or IL-1 also showed increased secretion of labeled triglyceride into the media. IFN-alpha stimulated the incorporation of 3H-glycerol into triglyceride by 39% after 72 hour's incubation. In contrast, IFN-gamma had no effect on lipogenesis in HepG2 cells. These data suggest that cytokines can directly stimulate the synthesis of triglycerides in cultured Hep G2 liver cells in vitro.
肿瘤坏死因子-α（TNF-α）、白细胞介素-1（IL-1）和干扰素α（IFN-α）在体内可刺激肝脏脂肪生成。我们现在发现，通过在培养的HepG2细胞中3H甘油掺入甘油三酯的量来衡量，TNF-α、IL-1和IFN-α可刺激脂肪生成。用TNF或IL-1将HepG2细胞孵育约24小时才能观察到脂肪生成的刺激作用，且这种作用在接下来的四天中会增强。孵育72小时后，TNF使脂肪生成增加2.4倍，而IL-1则使脂肪生成增加3.5倍。TNF刺激肝脏脂肪生成的半数最大浓度为4 ng/mL，而IL-1为0.3 ng/mL。用TNF或IL-1处理的细胞也显示出标记的甘油三酯向培养基中的分泌增加。孵育72小时后，IFN-α使3H甘油掺入甘油三酯的量增加39%。相比之下，IFN-γ对HepG2细胞的脂肪生成没有影响。这些数据表明，细胞因子在体外可直接刺激培养的HepG2肝细胞中甘油三酯的合成。
