Silybin regulates P450s activity by attenuating endoplasmic reticulum stress in mouse nonalcoholic fatty liver disease
Silybin regulates P450s activity by attenuating endoplasmic reticulum stress in mouse nonalcoholic fatty liver disease
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水飞蓟宾通过减轻小鼠非酒精性脂肪肝病的内质网应激来调节 P450s 活性
DOI：
10.1038/s41401-022-00924-4
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发表时间：
2022-06-15
影响因子：
8.2
通讯作者：
Xie，Yuan
中科院分区：
文献类型：
--
作者：
Wu，Jing;Lou，Yun-ge;Xie，Yuan
细胞色素P450是位于内质网上的重要Ⅰ相代谢酶，参与内源性和外源性物质的代谢。我们以前的研究表明，肝保护剂水飞蓟宾恢复CYP 3A在小鼠非酒精性脂肪性肝病（NAFLD）的表达。在这项研究中，我们研究了水飞蓟宾如何调节NAFLD期间P450的活性。C57 BL/6小鼠喂饲高脂饲料8周诱导NAFLD，并分别给予水飞蓟宾50、100 mg ·kg-1·d-1，i.g.在过去的4周里。我们发现，HFD摄入诱导肝脂肪变性和ER应激，导致肝微粒体中5种主要P450酶（包括CYP 1A 2、CYP 2B 6、CYP 2C 19、CYP 2D 6和CYP 3A）活性的显著抑制。这些变化被剂量依赖性逆转水飞蓟宾管理。在体外TG刺激的HepG 2细胞中也观察到水飞蓟宾的有益作用。为了阐明潜在的机制，我们研究了参与P450催化系统，膜磷脂和ER膜流动性的组分，发现细胞色素b5（cyt b5）在ER应激过程中显著下调，并且ER膜流动性也降低，证明了DPH极化和较低的多不饱和磷脂水平。NADP+/NADPH和PC/PE比值的增加提示线粒体功能障碍和细胞色素c（cytc）释放导致细胞内Ca ~（2+）释放和Ca ~（2+）稳态的破坏。细胞色素c与细胞色素b5的相互作用是内质网应激抑制P450活性的重要原因。水飞蓟宾的全程作用提示其可能通过抗内质网应激调节P450 s活性。我们的研究结果表明，ER应激可能是至关重要的抑制P450活性在小鼠NAFLD和水飞蓟宾调节P450活性通过减轻ER应激。
Cytochrome P450s are important phase I metabolic enzymes located on endoplasmic reticulum (ER) involved in the metabolism of endogenous and exogenous substances. Our previous study showed that a hepatoprotective agent silybin restored CYP3A expression in mouse nonalcoholic fatty liver disease (NAFLD). In this study we investigated how silybin regulated P450s activity during NAFLD. C57BL/6 mice were fed a high-fat-diet (HFD) for 8 weeks to induce NAFLD, and were administered silybin (50, 100 mg ·kg−1·d−1, i.g.) in the last 4 weeks. We showed that HFD intake induced hepatic steatosis and ER stress, leading to significant inhibition on the activity of five primary P450s including CYP1A2, CYP2B6, CYP2C19, CYP2D6, and CYP3A in liver microsomes. These changes were dose-dependently reversed by silybin administration. The beneficial effects of silybin were also observed in TG-stimulated HepG2 cells in vitro. To clarify the underlying mechanism, we examined the components involved in the P450 catalytic system, membrane phospholipids and ER membrane fluidity, and found that cytochrome b5 (cyt b5) was significantly downregulated during ER stress, and ER membrane fluidity was also reduced evidenced by DPH polarization and lower polyunsaturated phospholipids levels. The increased ratios of NADP+/NADPH and PC/PE implied Ca2+release and disruption of cellular Ca2+homeostasis resulted from mitochondria dysfunction and cytochromec(cytc) release. The interaction between cytcand cyt b5 under ER stress was an important reason for P450s activity inhibition. The effect of silybin throughout the whole course suggested that it regulated P450s activity through its anti-ER stress effect in NAFLD. Our results suggest that ER stress may be crucial for the inhibition of P450s activity in mouse NAFLD and silybin regulates P450s activity by attenuating ER stress.