Department of Emergency, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Intensive Care Unit, Nanjing DrumTower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China.
Shock. 2020 Feb;53(2):217-222. doi: 10.1097/SHK.0000000000001351.
The aim of this study was to investigate the changes of bile acids in the liver during hemorrhagic shock (HS) and their potential to attenuate liver injury via activation of SIRT1 (sirtuin 1)-FXR (farnesoid X receptor) signaling.
A Sprague-Dawley (SD) rat HS model was established, whereas HepG2 cells were hypoxically cultured to simulate HS in vitro. Liver bile acids (BA) were profiled with ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). FXR expression was detected by western blot and immunohistochemistry. The mRNA levels of SIRT1 and FXR were detected by polymerase chain reaction. Protein expression of SIRT1, FoxM1, NF-κB, acetyl-NF-κB, p53, and acetyl-p53 was analyzed by western blot. Hepatocyte apoptosis and proliferation were measured by TUNEL assay and Ki-67 staining, respectively. Serum and supernatant cytokines were analyzed using ELISA assays. Liver injury was also assessed. To investigate the possible mechanisms, SIRT1 agonist (SRT1720), SIRT1 inhibitor (EX527), and FXR inhibitor (Z-guggulsterone) were used.
Tauroursodeoxycholic acid (TUDCA) in the liver decreased significantly after HS. SIRT1 and FXR expression was time-dependently downregulated by HS or hypoxia condition. TUDCA upregulated SIRT1-FXR activity, which inhibited expression and acetylation of NF-κB and p53 and increased FoxM1 expression, leading to decreased inflammatory response and apoptosis and increased proliferative capacity in hepatocytes, and attenuation of liver injury. EX527 pretreatment reversed the protective effect of TUDCA. Moreover, Z-guggulsterone supplementation decreased the protective effect of TUDCA in vitro.
TUDCA in the liver decreased during HS. TUDCA supplementation might attenuate HS-induced liver injury by upregulating SIRT1-FXR signaling.
本研究旨在探讨失血性休克（HS）过程中肝脏胆汁酸的变化及其通过激活 SIRT1（沉默调节蛋白 1）-FXR（法尼醇 X 受体）信号减轻肝损伤的潜力。
建立 Sprague-Dawley（SD）大鼠 HS 模型，体外培养 HepG2 细胞模拟 HS。采用超高效液相色谱-串联质谱（UPLC-MS/MS）分析肝胆汁酸（BA）谱。采用 Western blot 和免疫组织化学检测 FXR 表达。采用聚合酶链反应检测 SIRT1 和 FXR 的 mRNA 水平。采用 Western blot 分析 SIRT1、FoxM1、NF-κB、乙酰化-NF-κB、p53 和乙酰化-p53 的蛋白表达。通过 TUNEL 检测和 Ki-67 染色分别检测肝细胞凋亡和增殖。采用 ELISA 法分析血清和上清液细胞因子。评估肝损伤。为了探讨可能的机制，使用 SIRT1 激动剂（SRT1720）、SIRT1 抑制剂（EX527）和 FXR 抑制剂（Z-吉格斯特龙）。
HS 后肝脏牛磺熊脱氧胆酸（TUDCA）明显减少。SIRT1 和 FXR 的表达随着 HS 或低氧条件呈时间依赖性下调。TUDCA 上调 SIRT1-FXR 活性，抑制 NF-κB 和 p53 的表达和乙酰化，增加 FoxM1 表达，导致炎症反应和凋亡减少，肝细胞增殖能力增加，减轻肝损伤。EX527 预处理逆转了 TUDCA 的保护作用。此外，Z-吉格斯特龙补充降低了 TUDCA 在体外的保护作用。
HS 时肝脏 TUDCA 减少。TUDCA 补充可能通过上调 SIRT1-FXR 信号减轻 HS 引起的肝损伤。
