Zhang Bingbing, Yang Wei, Zou Ying, Li Ming, Guo Han, Zhang Hongyou, Xia Cheng, Xu Chuang
College of Life Science and Technology, Daqing, China.
College of Animal Science and Technology, Heilongjiang Bayi Agricultural University, Daqing, China.
Cell Physiol Biochem. 2018;47(3):1310-1317. doi: 10.1159/000490226. Epub 2018 Jun 15.
BACKGROUND/AIMS: Non-esterified fatty acids (NEFAs) are important inducers of inflammatory responses and hepatic lipid accumulation, which lead to non-alcoholic fatty liver disease (NAFLD). High plasma NEFA is found in NAFLD patients, and associated with metabolic syndrome and type-2 diabetes. NFκB is known to upregulate Orai1, the Ca2+ channel responsible for store-operated Ca2+ entry. The present study explored the role of NEFA-sensitive NFκB-dependent Orai1 expression in the regulation of lipid synthesis.
BRL-3A rat liver hepatocyte lines were studied in the absence and presence of NEFA. Transcript and protein expression levels of factors involved in lipid synthesis were quantified by quantitative polymerase chain reaction (qPCR) and western blot analyses. Fatty acids were measured by immunofluorescence.
NEFA significantly increased, as indicated by the expression of sterol regulatory element-binding protein 1 (SREBP-1c), fatty acid synthase (FAS), acetyl-CoA carboxylase α (ACC1), Orai1, and NFκB p65 by qPCR and western blot analyses. These effects were reversed by the Orai1 inhibitor, 2-aminoethoxydiphenyl borate, and the NFκB inhibitor, wogonin. Furthermore, SREBP-1c, FAS, ACC1, and Orai1 were significantly decreased by Orai1 silencing.
Taken together, these results demonstrated that NEFA-sensitive NFκB-dependent Orai1 expression regulates de novo lipogenesis.
背景/目的：非酯化脂肪酸（NEFAs）是炎症反应和肝脏脂质蓄积的重要诱导因素，可导致非酒精性脂肪性肝病（NAFLD）。NAFLD患者血浆NEFA水平较高，且与代谢综合征和2型糖尿病相关。已知核因子κB（NFκB）可上调Orai1，Orai1是负责储存性钙内流的钙离子通道。本研究探讨了NEFA敏感的NFκB依赖性Orai1表达在脂质合成调控中的作用。
在有无NEFA的情况下对BRL-3A大鼠肝肝细胞系进行研究。通过定量聚合酶链反应（qPCR）和蛋白质免疫印迹分析对参与脂质合成的因子的转录和蛋白表达水平进行定量。通过免疫荧光法测定脂肪酸。
qPCR和蛋白质免疫印迹分析显示，NEFA显著增加了固醇调节元件结合蛋白1（SREBP-1c）、脂肪酸合酶（FAS）、乙酰辅酶A羧化酶α（ACC1）、Orai1和NFκB p65的表达。Orai1抑制剂2-氨基乙氧基二苯硼酸盐和NFκB抑制剂汉黄芩素可逆转这些作用。此外，Orai1沉默可使SREBP-1c、FAS、ACC1和Orai1显著降低。
综上所述，这些结果表明NEFA敏感的NFκB依赖性Orai1表达调节从头脂肪生成。
