Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, 3901 Rainbow Blvd, MS-1018, Kansas City, KS 66160, USA.
Toxicol Appl Pharmacol. 2011 Feb 1;250(3):256-62. doi: 10.1016/j.taap.2010.11.002. Epub 2010 Nov 9.
Cholestatic liver injury induced by alpha-naphthylisothiocyanate (ANIT) is provoked by injury to intrahepatic bile ducts and the progression of hepatic necrosis requires the procoagulant protein tissue factor (TF) and extrahepatic cells including neutrophils. Recent studies have shown that myeloid cell TF contributes to neutrophil activation. We tested the hypothesis that myeloid cell TF contributes to neutrophil activation in ANIT-treated mice. TF activity in liver homogenates increased significantly in TF(flox/flox) mice treated with ANIT, but not in TF(flox/flox)/LysMCre mice (TF(ΔMyeloid) mice), which have reduced TF expression in monocytes/macrophages and neutrophils. Myeloid cell-specific TF deficiency did not alter expression of the chemokines KC or MIP-2 but reduced hepatic neutrophil accumulation in ANIT-treated mice at 48 h as indicated by tissue myeloperoxidase (MPO) activity. Myeloid cell TF deficiency significantly reduced CD11b expression by blood neutrophils in ANIT-treated mice, and this was associated with reduced plasma MPO protein levels, an index of neutrophil degranulation. However, myeloid cell-specific TF deficiency had no effect on ANIT-induced coagulation cascade activation. The increase in serum ALT and ALP activities in ANIT-treated mice was reduced by myeloid cell TF deficiency (p<0.05), but the myeloid cell TF deficiency did not reduce hepatic necrosis at 48 h, as determined by histopathology and morphometry. The results suggest that myeloid cell TF contributes to neutrophil CD11b expression during cholestasis by a coagulation-independent pathway. However, the resultant reduction in neutrophil accumulation/activation is insufficient to substantially reduce ANIT hepatotoxicity, suggesting that myeloid cell TF is only one of many factors modulating hepatic necrosis during cholestasis.
α-萘异硫氰酸酯（ANIT）诱导的胆汁淤积性肝损伤是由肝内胆管损伤和肝坏死的进展引起的，需要促凝蛋白组织因子（TF）和包括中性粒细胞在内的肝外细胞。最近的研究表明，髓样细胞 TF 有助于中性粒细胞的激活。我们检验了髓样细胞 TF 有助于 ANIT 处理小鼠中性粒细胞激活的假说。在接受 ANIT 治疗的 TF(flox/flox)小鼠的肝匀浆中，TF 活性显著增加，但在 TF(flox/flox)/LysMCre 小鼠（TF(ΔMyeloid) 小鼠）中没有增加，后者在单核细胞/巨噬细胞和中性粒细胞中 TF 表达减少。髓样细胞特异性 TF 缺陷不改变趋化因子 KC 或 MIP-2 的表达，但可减少 ANIT 处理小鼠 48 小时时肝内中性粒细胞的积聚，这可通过组织髓过氧化物酶（MPO）活性来指示。髓样细胞特异性 TF 缺陷显著降低了 ANIT 处理小鼠血液中性粒细胞中的 CD11b 表达，这与血浆 MPO 蛋白水平降低有关，后者是中性粒细胞脱颗粒的指标。然而，髓样细胞特异性 TF 缺陷对 ANIT 诱导的凝血级联激活没有影响。髓样细胞 TF 缺陷可降低 ANIT 处理小鼠血清 ALT 和 ALP 活性的升高（p<0.05），但髓样细胞 TF 缺陷并不能减少 48 小时时的肝坏死，这可通过组织病理学和形态计量学来确定。结果表明，在胆汁淤积期间，髓样细胞 TF 通过非凝血途径促进中性粒细胞 CD11b 的表达。然而，中性粒细胞积聚/激活的减少不足以显著降低 ANIT 的肝毒性，这表明髓样细胞 TF 仅是调节胆汁淤积期间肝坏死的众多因素之一。
