Kupffer细胞抑制剂GdCl3对免疫性肝损伤保护作用的研究

目的:观察GdCl3对免疫性肝损伤保护效应,探讨Kupffer细胞活性在免疫性肝损伤形成中的作用.方法:建立卡介苗(BCG)和脂多糖(LPS)诱导的小鼠免疫性肝损伤模型(ip lmg·kg1BCG,7天后ip 0.2mg·kg1LPS,6h后处理动物),同时一次性给予20mg·kg1GdCl3.测定sALT、sGST活性及肝组织GSH含量;PT-PCR法测定肿瘤坏死因子(TNF-alpha)在肝组织中mRNA的丰度;免疫组化学研究凋亡相关基因Bcl-2、Bax的表达;光镜观察肝组织形态学变化.结果:免疫性肝损伤小鼠肝中TNF-alpah mRNA表达和促凋亡基因Bax表达明显上调;凋亡抑制基因Bcl-2表达显著下调;GdCl3能明显逆转上述指标,降低血清ALT、GST水平,升高肝中GSH含量,改善组织损伤.结论:Kupffer细胞选择性阻断剂GdCl3能明显保护免疫性肝损伤,其作用机制与抑制Krpffer细胞活性,减少TNF-alpha释放及肝细胞的凋亡有关.提示Kupffer细胞活性在肝损伤形成过程中起着重要的作用.

GdCl3对小鼠肝脏再生早期Cyp7A1基因转录的影响

目的:探讨小鼠肝脏再生早期氯化钆(GdCl3)通过作用于枯否细胞影响胆酸介导的Cyp7A1基因转录的抑制.方法:运用GdCl3(10 mg/kg,iv.)或PBS(0.2 mL,iv.)处理C57BL/6小鼠24 h后,切除小鼠70%的肝脏,于术后第1日处死小鼠,收集肝脏,采用实时定量RT-PCR方法检测肝脏中Cyp7A1,TNFα和IL-6基因的表达.结果:肝脏再生的第1日,与PBS对照组相比,GdCl3处理组中Cyp7A1 mRNA的表达降低(P＜0.01),而细胞因子TNAα和IL-6 mRNA的表达升高(P＜0.01).结论:在肝脏再生的早期,GdCl3可增进胆酸介导Cyp7A1基因转录的抑制,这种作用是通过促使枯否细胞产生细胞因子TNFa和IL-6来实现.

BACKGROUND: Gadolinium chloride (GdCl3) selectively in-activates Kupffer cells and protects against ischemia/reperfu-sion and endotoxin injury. However, the effect of Kupffer cell inactivation on liver regeneration after partial liver transplan-tation (PLTx) is not clear. This study was to investigate the role of GdCl3 pretreatment in graft function after PLTx, and to explore the potential mechanism involved in this process.
METHODS: PLTx (30% partial liver transplantation) was per-formed using Kamada's cuff technique, without hepatic artery reconstruction. Rats were randomly divided into the control low-dose (5 mg/kg) and high-dose (10 mg/kg) GdCl3 groups. Liver injury was determined by the plasma levels of alanine aminotransferase and aspartate aminotransferase, liver regen-eration by PCNA staining and BrdU uptake, apoptosis by TU-NEL assay. IL-6 and p-STAT3 levels were measured by ELISA and Western blotting.
RESULTS: GdCl3 depleted Kupffer cells and decreased animal survival rates, but did not significantly affect alanine amino-transferase and aspartate aminotransferase (P>0.05). GdCl3 pretreatment induced apoptosis and inhibited IL-6 overex-pression and STAT3 phosphorylation after PLTx in graft tissues.
CONCLUSION: Kupffer cells may contribute to the liver re-generation after PLTx through inhibition of apoptosis and activation of the IL-6/p-STAT3 signal pathway.