The effect of enterolactone on sphingolipid pathway and hepatic insulin resistance development in HepG2 cells
The effect of enterolactone on sphingolipid pathway and hepatic insulin resistance development in HepG2 cells
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DOI：
10.1016/j.lfs.2018.11.044
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发表时间：
2019-01-15
期刊：
影响因子：
6.1
通讯作者：
Konstantynowicz-Nowicka, Karolina
中科院分区：
文献类型：
--
作者：
Charytoniuk, Tomasz;Ilowska, Nicoletta;Konstantynowicz-Nowicka, Karolina
目的：肥胖和2型糖尿病与神经鞘脂类组织浓度升高有关，神经鞘脂直接干扰胰岛素信号转导途径。植物雌激素是一组植物来源的化合物，已被研究用于治疗代谢障碍。因此，本研究的目的是确定肠内酯(Enl)是一种常见的植物雌激素，在脂质过载状态下是否会影响鞘磷脂代谢，减少肝脏胰岛素抵抗的发生。主要方法：在HepG2细胞上，用enl和/或棕榈酸(PA)孵育16h，用高效液相色谱法测定细胞内外鞘磷脂的浓度。免疫印迹法检测鞘磷脂途径酶、细胞凋亡和胰岛素信号通路蛋白以及糖代谢调节剂的表达。主要结果：在HepG2细胞中，ENL+PA组细胞内神经酰胺和鞘氨醇浓度显著升高，同时细胞外神经酰胺浓度也显著增加。ENL处理增加了神经酰胺合成途径中部分酶的表达，降低了神经酰胺转运蛋白的表达。我们还观察到，在含有PA的ENL暴露后，胰岛素刺激的AKT和AMPK的磷酸化表达减少。我们的研究表明，ENL与PA共同作用后，caspase-3的表达增加。
Aims: Obesity and type 2 diabetes mellitus, correlate with increased tissue concentration of sphingolipids, which directly interfere with insulin signaling pathway. Phytoestrogens are a group of plant-derived compounds that have been studied in the case of metabolic disorders treatment. Therefore, the aim of this study was to ascertain whether enterolactone (ENL), a commonly known phytoestrogen, may affect sphingolipid metabolism and decrease hepatic insulin resistance development in a lipid overload state.Main methods: The study was conducted on HepG2 cells incubated with ENL and/or palmitic acid (PA) for 16 h. Intra- and extracellular sphingolipid concentrations were assessed by high performance liquid chromatography. The expression of sphingolipid pathway enzymes, apoptosis and insulin signaling pathway proteins and glucose metabolism regulators were evaluated by Western Blot.Key findings: In HepG2 cells, a considerable augmentation of intracellular ceramide and sphingosine concentration in ENL with PA group were indicated with simultaneous increase in extracellular ceramide concentration. The ENL treatment increased expression of selected enzymes from de novo ceramide synthesis pathway with lower expression of ceramide transfer protein. We also observed a decreased expression of insulin-stimulated phosphorylation of AKT and AMPK after exposure to ENL with PA. Our research demonstrated that ENL with PA resulted in an increased expression of caspase-3.