Research Center for Biopharmaceutics and Pharmacokinetics, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou, China.
Integrated Chinese and Western Medicine Postdoctoral research station, Jinan University, 601 Huangpu Avenue West, Guangzhou, China.
Theranostics. 2018 Oct 22;8(19):5246-5258. doi: 10.7150/thno.28676. eCollection 2018.
The role of small heterodimer partner (SHP) in regulation of xenobiotic detoxification remains elusive. Here, we uncover a critical role for SHP in circadian regulation of cytochromes P450 (CYPs) and drug-induced hepatotoxicity. The mRNA and protein levels of CYPs in the livers of wild-type and SHP mice were measured by quantitative real-time polymerase chain reaction and Western blotting, respectively. Regulation of CYP by SHP was investigated using luciferase reporter, mobility shift, chromatin immunoprecipitation, and/or co-immunoprecipitation assays. The circadian rhythmicities of xenobiotic-detoxifying CYP mRNAs and proteins were disrupted in SHP-deficient mice. Of note, SHP ablation up-regulated and , whereas it down-regulated all other genes. Moreover, SHP regulated the expression of genes through different mechanisms. SHP repressed Lrh-1/Hnf4α to down-regulate Cyp2c38, E4bp4 to up-regulate Cyp2a5, Dec2/HNF1α axis to up-regulate Cyp1a2, Cyp2e1 and Cyp3a11, and Rev-erbα to up-regulate Cyp2b10, Cyp4a10 and Cyp4a14. Furthermore, SHP ablation sensitized mice to theophylline (or mitoxantrone)-induced toxicity. Higher level of toxicity was correlated with down-regulated metabolism and clearance of theophylline (or mitoxantrone). In contrast, SHP ablation blunted the circadian rhythmicity of acetaminophen-induced hepatotoxicity and alleviated the toxicity by down-regulating Cyp2e1-mediated metabolism and reducing formation of the toxic metabolite. Toxicity alleviation by SHP ablation was also observed for aflatoxin B1 due to reduced formation of the toxic epoxide metabolite. SHP participates in circadian regulation of CYP enzymes, thereby impacting xenobiotic metabolism and drug-induced hepatotoxicity.
小异二聚体伴侣（SHP）在调节外来化合物解毒中的作用仍然难以捉摸。在这里，我们揭示了 SHP 在昼夜节律调节细胞色素 P450（CYPs）和药物诱导的肝毒性中的关键作用。通过定量实时聚合酶链反应和 Western blot 分别测量野生型和 SHP 小鼠肝脏中 CYP 的 mRNA 和蛋白质水平。使用荧光素酶报告基因、迁移率变动、染色质免疫沉淀和/或共免疫沉淀测定来研究 SHP 对 CYP 的调节。在 SHP 缺陷小鼠中，外来化合物解毒 CYP mRNAs 和蛋白质的昼夜节律性被打乱。值得注意的是，SHP 缺失上调了和，而下调了所有其他基因。此外，SHP 通过不同的机制调节基因的表达。SHP 抑制 Lrh-1/Hnf4α 以下调 Cyp2c38，E4bp4 上调 Cyp2a5，Dec2/HNF1α 轴上调 Cyp1a2、Cyp2e1 和 Cyp3a11，以及 Rev-erbα 上调 Cyp2b10、Cyp4a10 和 Cyp4a14。此外，SHP 缺失使小鼠对茶碱（或米托蒽醌）诱导的毒性敏感。更高的毒性水平与茶碱（或米托蒽醌）的代谢和清除率降低有关。相比之下，SHP 缺失削弱了对乙酰氨基酚诱导的肝毒性的昼夜节律性，并通过下调 Cyp2e1 介导的代谢和减少有毒代谢物的形成来减轻毒性。由于有毒环氧化物代谢物形成减少，SHP 缺失也减轻了黄曲霉毒素 B1 的毒性。SHP 参与 CYP 酶的昼夜节律调节，从而影响外来化合物代谢和药物诱导的肝毒性。
