Expression data of liver tissues from rats with and without methapyrilene treatment

We investigated a drug-induced liver injury (DILI) model in rats induced by methapyrilene (MPy) administration. MPy, a former antihistamine and anticholinergic drug, was withdrawn in the 1970ties due to its ability to initiate hepatocarcinogenesis and is now used to induce hepatobiliary injury and biliary epithelial cell hyperplasia. Male Wistar rats (8–10 weeks old, weighing 170–200 g) were randomly assigned to three dosing groups (n=6 per group and time-point) and dosed with MPy at 0, 30 and 80 mg/kg/day by oral gavage. After 4, 8 or 15 days, or after 14 days followed by a recovery period of 10 days (day 24) rats were sacrificed. Increased levels of ALAT, ASAT, AP and ɣ-GT as well as bili-t and total bile acids indicated liver damage (AP and ɣGT indicating biliary effects). They were detectable on day 7 at the high dose of 80 mg/kg MPy and persisted until day 15 at end of treatment. Histopathologically, vacuolation and necrosis of the hepatocytes (predominantly in the periportal region) were seen starting on day 3 - especially in animals treated with 80 mg/kg MPy. These findings were accompanied by periportal mononuclear inflammatory cell filtration. Bile duct proliferation, bile duct hyperplasia and increased numbers of mitoses of hepatocytes were evident at all treatment time points. The frequency and severity of these findings increased with dose and duration of the treatment. Gene expression analysis in liver tissues revealed highly significant transcriptional changes in the high dose group, detectable on day 4 and intensifying over time. Besides genes associated with apoptosis (CASP4, CASP12), detoxification (CYB4B) and proliferation (p21, CCNG1) several were related to bile acid metabolism or transport. For example, bile acid exporters OATP1, NTCP, OATP4 and MOAT1/ OATPB as well as the putative bile acid metabolizing enzymes AMACR, BAAT and ACOX2 were found down regulated in response to MPy treatment. In contrast, mRNAs encoding putative bile acid importers MRP2 and ABCC4 / MRP4 were found up regulated. Most of the deregulated levels returned to control values during the recovery phase except OATP1, MOAT1/ OATPB, which remained slightly elevated. Interestingly, OATP4 followed an inverse trend of deregulation after 10 days of recovery, presumably due to overcompensation. Overall, the expression changes found associated with bile acid metabolism or transport could be linked to detected bile acid level alterations in liver and plasma.本研究构建了甲氧吡林（methapyrilene, MPy）诱导的大鼠药物性肝损伤（drug-induced liver injury, DILI）模型。甲氧吡林是一种曾应用于临床的抗组胺与抗胆碱能药物，于20世纪70年代因可诱发肝致癌作用而退市，目前常被用于诱导肝胆损伤及胆管上皮细胞增生。 选取8~10周龄、体重170~200g的雄性Wistar大鼠，按随机原则分为3个给药组（每个剂量组及每个时间点n=6），通过灌胃方式分别给予0、30、80mg/kg/天的MPy。分别在给药后第4、8、15天，以及给药14天后恢复饲养10天（即第24天）时处死大鼠。 血清丙氨酸氨基转移酶（ALAT）、天冬氨酸氨基转移酶（ASAT）、碱性磷酸酶（AP）及γ-谷氨酰转移酶（ɣ-GT）水平升高，同时伴随总胆红素（bili-t）及总胆汁酸水平上升，提示存在肝损伤（其中AP与ɣ-GT可反映胆管损伤情况）。在80mg/kg高剂量组的第7天即可检测到上述指标异常，并持续至给药结束后的第15天。 组织病理学观察显示，肝细胞空泡变性及坏死（主要见于汇管区周围）于给药后第3天开始出现，尤以80mg/kg剂量组最为显著，同时伴随汇管区周围单核炎性细胞浸润。各给药时间点均可见胆管增殖、胆管增生及肝细胞有丝分裂数增加，且这些病变的发生率与严重程度随给药剂量及时长的增加而升高。 对肝组织进行基因表达分析发现，高剂量组出现了极具统计学意义的转录变化，该变化于给药后第4天即可检测到，并随时间推移逐渐加剧。除与细胞凋亡（CASP4、CASP12）、解毒作用（CYB4B）及细胞增殖（p21、CCNG1）相关的基因外，还有诸多基因与胆汁酸代谢或转运相关。例如，胆汁酸输出蛋白OATP1、NTCP、OATP4及MOAT1/OATPB，以及潜在的胆汁酸代谢酶AMACR、BAAT和ACOX2的表达均在MPy处理后下调。与之相反，编码胆汁酸输入蛋白的mRNA MRP2及ABCC4/MRP4的表达则出现上调。在恢复期，大多数失调基因的表达水平可恢复至对照组水平，但OATP1、MOAT1/OATPB的表达仍轻度升高。值得注意的是，恢复饲养10天后，OATP4的表达失调趋势出现反转，推测这是过度补偿效应所致。 总体而言，本研究检测到的与胆汁酸代谢及转运相关的基因表达变化，与肝脏及血浆中检测到的胆汁酸水平改变具有相关性。