急性肝衰竭大鼠TLR4 mRNA表达、血清肿瘤坏死因子-α、白介素-10及肝细胞凋亡的动态变化

目的观察急性内毒素性肝衰竭大鼠肝组织中TLR4mRNA表达变化规律及其与血清肿瘤坏死因子-α水平、肝细胞凋亡的关系。方法雌性Wistar大鼠D-氨基半乳糖/脂多糖同时腹腔注射,计算动物死亡率及生存时间,动态观察给药后4、8、12h肝功能、血清肿瘤坏死因子-α、IL-10、肝组织TLR4mRNA表达及病理变化,et TUNEL法检测原位细胞凋亡,计算凋亡指数。结果80%大鼠死于急性肝衰竭,平均生存时间为(15.6±1.8)h,病理表现为肝脏大面积或亚大面积坏死。给药后4、8、12h血清TNF-α含量及肝细胞凋亡指数均增加,肝组织TLR4mRNA的表达在各时间点均增加并与血清TNF-α含量呈正相关(r=0.709,P=0.000),与IL-10无相关性。结论内毒素通过单核吞噬系统TLR4介导TNF-α大量产生,激活炎症级联反应并诱导肝细胞凋亡是内毒素性肝衰竭的重要病理机制之一,阻断肝内外单核吞噬系统TLR4介导的生理学作用,可能对内毒素性肝衰竭起到一定防治作用。

Kinetic Changes of TLR4 mRNA Expression TNF-α, IL-10 and Hepatocytes Apoptosis of D-galactosamine/lipopolysaccharide Induced Acute Liver Failure in Rats

Objective To describe the kinesis changes of TLR4 mRNAexpression,serum TNF-α and heaptocyte apoptosis in lipopolysaccharide(LPS)-induced acute liver failure.Methods Acute liver failure was established by intraperitoneal injections of D-galactosamine(400 mg/kg)and lipopolysaccharide(100 ug/kg)in female Wistar rats.Mortality and survival time were recorded in₁₀ rats.Ten rats were sacrificed at 4,8,and 12 hours after treatment.Liver function test,serum TNF-α levels,IL-10 were measured,as well liver pathology studied.The apoptosis of liver cells was detected by TUNELassay.Results 80% rats died from acute liver failure after administration of D-galactosamine/lipopolysaccharide,with mean survival time of(15.6±1.8)hours.Liver function tests were compatible with liver massive necrosis.Plasma level of TNF-α and liver cells apoptosis increased,The expression of TLR4 mRNAincreased at every time points in liver tissue,which was positively correlation with concentration of plasma TNF-α(r=0.709,P=0.000)and no correlation with IL-10.Conclusion The results showed that TLR4 were involved in inducing the generous production of TNF-α,which activating inflammatory cascade reaction and initiating liver cell apoptosis.It suggested that TLR4 would be the novel strategy to prevent the development of lipopolysaccharide-induced acute liver failure.