二烯丙基二硫抑制 HepG2 细胞载脂蛋白(a)的表达通过 MEK1-ERK1/2-ELK-1 通路。
Diallyl disulphide inhibits apolipoprotein(a) expression in HepG2 cells through the MEK1-ERK1/2-ELK-1 pathway.
机构信息
Department of Cardiology, Affiliated Nanhua Hospital of University of South China, Hengyang, 421001, China.
Institute of Cardiovascular disease, Key Laboratory for Atherosclerology of Human Province, University of South China, Hengyang, 421001, China.
出版信息
Lipids Health Dis. 2017 Nov 25;16(1):223. doi: 10.1186/s12944-017-0616-1.
BACKGROUND
Lipoprotein(a) [LP(a)] is implicated as a common and independent risk factor for cardiovascular diseases. The therapeutic options currently available for reducing plasma LP(a) concentrations are limited. Diallyl disulphide (DADS), the main component of garlic, regulates lipid metabolism in hepatocytes and adipocytes through ERK1/2 signalling. This study aimed to assess the effect of DADS on apolipoprotein(a) [apo(a)] in HepG2 cells. We also determined the effects of DADS on apo(a) expression and secretion in HepG2 cells as well as the underlying mechanisms.
METHODS
We examined the role of DADS on apo(a) expression in HepG2 cells by treating cell with different concentrations of DADS (10, 20, 40 and 80 μg/mL) for 24 h or treating cells with 40 μg/mL DADS for 0, 6, 12, 24 and 48 h. Then we used quantitative real-time PCR to analysis apo(a) mRNA levels, used Western blot to analysis apo(a) protein levels and used enzyme-linked immunosorbent assay to test apo(a) secreted levels. To farther determined the role of DADS, we applied Transfection of small interfering RNA to knockdown ELK-1levels and applied PD98059, a specific inhibitor of ERK1/2, to block ERK1/2 signal.
RESULTS
The results show DADS inhibited apo(a) at both the mRNA and protein levels in HepG2 cells in a dose-dependent manner. DADS-mediated inhibition of apoa(a) expression in HepG2 cells was attenuated when the cells were cultured in medium containing PD98059 (ERK1/2 inhibitor) or were transfected with siRNAs against MEK1 or ELK-1. Overexpression of apo(a) yielded similar results.
CONCLUSIONS
This study reveals that DADS can downregulate apo(a) expression in a dose-dependent manner via the MEK-ERK12-ELK-1 pathway.
背景
脂蛋白(a)[LP(a)]被认为是心血管疾病的一个常见且独立的危险因素。目前可用于降低血浆 LP(a)浓度的治疗选择有限。二烯丙基二硫（DADS）是大蒜的主要成分，通过 ERK1/2 信号调节肝细胞和脂肪细胞中的脂质代谢。本研究旨在评估 DADS 对 HepG2 细胞载脂蛋白(a)[apo(a)]的影响。我们还确定了 DADS 对 HepG2 细胞中 apo(a)表达和分泌的影响及其潜在机制。
方法
我们通过用不同浓度的 DADS（10、20、40 和 80 μg/mL）处理细胞 24 h 或用 40 μg/mL DADS 处理细胞 0、6、12、24 和 48 h 来研究 DADS 对 HepG2 细胞中 apo(a)表达的作用。然后，我们使用定量实时 PCR 分析 apo(a)mRNA 水平，使用 Western blot 分析 apo(a)蛋白水平，使用酶联免疫吸附测定法检测 apo(a)分泌水平。为了进一步确定 DADS 的作用，我们应用小干扰 RNA 转染以敲低 ELK-1 水平，并应用 PD98059（ERK1/2 的特异性抑制剂）阻断 ERK1/2 信号。
结果
结果表明，DADS 以剂量依赖性方式抑制 HepG2 细胞中的 apo(a)mRNA 和蛋白水平。当细胞在含有 PD98059（ERK1/2 抑制剂）的培养基中培养或用针对 MEK1 或 ELK-1 的 siRNAs 转染时，DADS 介导的 HepG2 细胞中 apo(a)表达的抑制作用减弱。过表达 apo(a)也得到了类似的结果。
结论
本研究表明，DADS 可以通过 MEK-ERK12-ELK-1 途径以剂量依赖性方式下调 apo(a)表达。
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