Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
Shock. 2013 Aug;40(2):115-21. doi: 10.1097/SHK.0b013e318299d1a7.
Ischemia/reperfusion (I/R) of the liver contributes to the pathobiology of liver injury in transplantation, liver surgery, and hemorrhagic shock. Ischemia/reperfusion induces an inflammatory response that is driven, in part, by Toll-like receptor 4 (TLR) signaling. CD14 is known to participate in the function of TLR4. We hypothesized that CD14 would be involved in the pathobiology of warm hepatic I/R.
Using a 70% liver inflow inclusion model, CD14 knockout and wild-type (WT) mice were subjected to 1-h warm ischemia followed by reperfusion. CD14 mRNA, circulating transaminase, interleukin 6, soluble CD14, and high-mobility group box 1 (HMGB1) levels were measured. CD14 neutralizing antibody or isotype control antibody was given before ischemia or reperfusion for CD14 blockade in WT mice. Recombinant HMGB1 was given before reperfusion in some experiments to test if liver injury worsens.
There was an upregulation of CD14 mRNA in reperfused livers together with increased soluble CD14 levels in the circulation. Compared with WT control mice, CD14 knockout mice had much lower alanine aminotransferase and interleukin 6 levels at 6 and 24 h following I/R, and much less liver necrosis by histology. TUNEL (terminal deoxynucleotidyl-transferase dUTP nick end labeling) staining displayed less apoptosis at 24 h in the absence of CD14. CD14 blockage by neutralizing antibody also attenuated liver injury and the inflammatory response in C57BL/6 mice following I/R, but did not provide additional protection to TLR4 mutant C3H/Hej mice. CD14 deficiency did not change circulating HMGB1 levels following I/R (6 h). A dose of recombinant HMGB1, which worsened hepatic injury when given before reperfusion in WT mice, did not increase liver damage in CD14-deficient mice.
CD14 is actively involved in hepatic I/R injury. Its deficiency or blockade ischemia attenuates liver injury and inflammatory response. CD14 mediates liver damage and inflammatory responses in the setting of warm hepatic I/R in mice.
肝脏的缺血/再灌注（I/R）导致移植、肝外科和失血性休克中的肝损伤的病理生物学变化。缺血/再灌注诱导炎症反应，部分由 Toll 样受体 4（TLR）信号驱动。已知 CD14 参与 TLR4 的功能。我们假设 CD14 参与热肝 I/R 的病理生物学变化。
使用 70%肝流入包容模型，将 CD14 敲除和野生型（WT）小鼠进行 1 小时的热缺血，然后再灌注。测量 CD14mRNA、循环转氨酶、白细胞介素 6、可溶性 CD14 和高迁移率族蛋白 B1（HMGB1）水平。在 WT 小鼠中，在缺血或再灌注前给予 CD14 中和抗体或同种型对照抗体进行 CD14 阻断。在一些实验中，在再灌注前给予重组 HMGB1，以测试肝损伤是否恶化。
与 WT 对照组相比，再灌注肝脏中的 CD14mRNA 上调，循环中的可溶性 CD14 水平升高。CD14 敲除小鼠在 I/R 后 6 和 24 小时的丙氨酸转氨酶和白细胞介素 6 水平较低，组织学上的肝坏死较少。TUNEL（末端脱氧核苷酸转移酶 dUTP 缺口末端标记）染色显示，在没有 CD14 的情况下，24 小时时凋亡减少。在 I/R 后，用中和抗体阻断 CD14 也减轻了 C57BL/6 小鼠的肝损伤和炎症反应，但对 TLR4 突变 C3H/Hej 小鼠没有提供额外的保护。I/R 后，CD14 缺乏不会改变循环中 HMGB1 水平（6 小时）。在 WT 小鼠中，再灌注前给予重组 HMGB1 会加重肝损伤，但在 CD14 缺陷小鼠中不会增加肝损伤。
CD14 积极参与肝 I/R 损伤。其缺乏或阻断缺血减轻肝损伤和炎症反应。在小鼠热肝 I/R 中，CD14 介导肝损伤和炎症反应。
