Huynh Toan, Nguyen Nhat, Keller Steven, Moore Cathy, Shin Min C, McKillop Iain H
F.H. Sammy Ross Jr. Trauma Center, Carolinas Medical Center, Charlotte, North Carolina 28232-2861, USA.
J Trauma. 2010 Aug;69(2):360-7. doi: 10.1097/TA.0b013e3181e65133.
Leukocyte trafficking may induce hepatic dysfunction in sepsis. Herein, we hypothesize that reduction in leukocyte adhesion and, hence, leukocyte-endothelial interaction by activated protein C (aPC) may preserve hepatic function after sepsis.
Rats underwent sham or cecal ligation and puncture, followed by saline or aPC (1 mg/kg intravenously) infusion, twice daily for 4 days. Cytokine levels were determined by enzyme-linked immunosorbent assay. Liver function and injury were assessed by bile production and plasma aspartate transaminase, respectively. In parallel experiments, neutrophils were labeled with Rhodamine 6G, and trafficking determined by cell motion tracking using intravital microscopy. Leukocyte trafficking and traveling velocity were computed at baseline and at 10 minutes and 40 minutes after endothelin-1 infusion.
Sepsis induced 90% mortality and elevated levels of interleukin (IL)-2 (167 pg/mL +/- 39 pg/mL vs. 68 pg/mL +/- 2 pg/mL, p < 0.05), IL-6 (5,806 pg/mL +/- 3,389 pg/mL vs. 0 pg/mL +/- 0 pg/mL, p < 0.05), and IL-8 (492 pg/mL +/- 22 pg/mL vs. 21 pg/mL +/- 17 pg/mL, p < 0.05). Aspartate transaminase levels increased (227 IU/L +/- 14 IU/L vs. 51 IU/L +/- 7 IU/L, p < 0.05) in cecal ligation and puncture animals, whereas bile production decreased by fivefold compared with sham (436 microg/kg/h +/- 247 microg/kg/h vs. 2,357 microg/kg/h +/- 147 microg/kg/h, p < 0.05). Hepatic leukocyte adhesion increased threefold in septic animals (42.7 WBC per image +/- 7.3 WBC per image vs. 14.8 WBC per image +/- 3.8 WBC per image, p < 0.01), whereas leukocyte velocity decreased compared with sham (10.5 microm/s +/- 2.2 microm/s vs. 22.3 microm/s +/- 2.4 microm/s, p < 0.01). By contrast, aPC treatment reduced mortality to 60%, attenuated inflammatory cytokines, reduced leukocyte trafficking, and preserved hepatic function.
Our data demonstrate that sepsis may, in part, induce hepatic dysfunction by augmenting leukocyte trafficking into hepatic sinusoids. Treatment with aPC attenuated leukocyte trafficking and, in doing so, preserved hepatic function and improved survival. Collectively, these data suggest an important role for protein C-dependent leukocyte-endothelial interaction in sepsis.
白细胞运输可能在脓毒症中诱发肝功能障碍。在此，我们假设活化蛋白C（aPC）减少白细胞黏附，进而减少白细胞与内皮细胞的相互作用，可能在脓毒症后保护肝功能。
对大鼠进行假手术或盲肠结扎穿孔术，随后每天两次静脉输注生理盐水或aPC（1mg/kg），持续4天。通过酶联免疫吸附测定法测定细胞因子水平。分别通过胆汁生成和血浆天冬氨酸转氨酶评估肝功能和肝损伤。在平行实验中，用罗丹明6G标记中性粒细胞，并使用活体显微镜通过细胞运动跟踪确定运输情况。在内皮素-1输注后基线、10分钟和40分钟时计算白细胞运输和移动速度。
脓毒症导致90%的死亡率，并使白细胞介素（IL）-2（167pg/mL±39pg/mL对68pg/mL±2pg/mL，p<0.05）、IL-6（5806pg/mL±3389pg/mL对0pg/mL±0pg/mL，p<0.05）和IL-8（492pg/mL±22pg/mL对21pg/mL±17pg/mL，p<0.05）水平升高。盲肠结扎穿孔术动物的天冬氨酸转氨酶水平升高（227IU/L±14IU/L对51IU/L±7IU/L，p<0.05），而与假手术组相比胆汁生成减少了五倍（436μg/kg/h±247μg/kg/h对2357μg/kg/h±147μg/kg/h，p<0.05）。脓毒症动物肝脏白细胞黏附增加了两倍（每个图像42.7个白细胞±7.3个白细胞对每个图像14.8个白细胞±3.8个白细胞，p<0.01），而与假手术组相比白细胞速度降低（10.5μm/s±2.2μm/s对22.3μm/s±2.4μm/s，p<0.01）。相比之下，aPC治疗使死亡率降至60%，减轻了炎性细胞因子，减少了白细胞运输，并保护了肝功能。
我们的数据表明，脓毒症可能部分通过增加白细胞向肝血窦的运输来诱发肝功能障碍。aPC治疗减轻了白细胞运输，从而保护了肝功能并提高了生存率。总体而言，这些数据表明蛋白C依赖性白细胞与内皮细胞的相互作用在脓毒症中起重要作用。
