Division of Transplant Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin.
Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin.
J Surg Res. 2019 Mar;235:73-82. doi: 10.1016/j.jss.2018.09.057. Epub 2018 Oct 24.
The effect of hepatic ischemia-reperfusion injury (IRI) on bile transporter (BT) gene expression is unknown. We hypothesized that abnormal expression of BTs during hepatic IRI is dependent on nuclear factor erythroid 2-related factor 2 (NRF2), which contributes to the cholestasis after reperfusion.
Sham surgery and short (60 min) or long (90 min) periods of warm ischemia time (WIT) with or without reperfusion for 24 h were applied to wild-type Sprague-Dawley rats and Nrf2 knockout rats (n = 5 per group). At each stage of IRI, the serum levels of aminotransferase, total bilirubin, and bile acids were measured. In addition, hepatic tissue was sampled to determine the histologic score of IRI (Suzuki score), measure adenosine triphosphate (ATP), and identify the quantitative real-time polymerase chain reactions of BTs (Oatp1, Ntcp, Mrp2, Bsep, and Mrp3).
In short periods of WIT, BT expression increased during the ischemia stage and returned to the baseline after reperfusion. However, in long periods of WIT, BT expression did not increase after ischemia and decreased further after reperfusion. Short WIT did not increase BT expression in Nrf2 knockout animals. The level of BT expression was correlated with the Suzuki score, the serum levels of aminotransferase, bilirubin, and bile acids, and tissue ATP level. Stepwise multiple regression analysis derived equations to predict the Suzuki score (R = 76.8, P < 0.001), serum total bilirubin (R = 61.2, P < 0.001), and tissue ATP (R = 61.1, P < 0.001).
Short WIT induces the transcriptional activities of BT, whereas long WIT depresses them, and the effect was blunted by Nrf2 knockout status. BT expression can be considered a surrogate marker for hepatic IRI.
肝缺血再灌注损伤（IRI）对胆盐转运体（BT）基因表达的影响尚不清楚。我们假设，肝IRI 期间 BTs 的异常表达依赖于核因子红细胞 2 相关因子 2（NRF2），这有助于再灌注后的胆汁淤积。
对野生型 Sprague-Dawley 大鼠和 Nrf2 敲除大鼠（每组 5 只）进行假手术和短（60 分钟）或长（90 分钟）热缺血时间（WIT），并分别在再灌注 24 小时后进行。在 IRI 的每个阶段，均测量血清转氨酶、总胆红素和胆汁酸水平。此外，还采集肝组织以确定 IRI 的组织学评分（Suzuki 评分）、测量三磷酸腺苷（ATP）并鉴定 BTs 的定量实时聚合酶链反应（Oatp1、Ntcp、Mrp2、Bsep 和 Mrp3）。
在 WIT 时间较短的情况下，BT 表达在缺血期增加，再灌注后恢复到基线。然而，在 WIT 时间较长的情况下，BT 表达在缺血后没有增加，再灌注后进一步下降。Nrf2 敲除动物的短 WIT 并未增加 BT 表达。BT 表达水平与 Suzuki 评分、血清转氨酶、胆红素和胆汁酸水平以及组织 ATP 水平相关。逐步多元回归分析得出了预测 Suzuki 评分（R=76.8，P<0.001）、血清总胆红素（R=61.2，P<0.001）和组织 ATP（R=61.1，P<0.001）的方程。
短 WIT 诱导 BT 的转录活性，而长 WIT 抑制它们，Nrf2 敲除状态削弱了这种作用。BT 表达可以被视为肝 IRI 的替代标志物。
