Andus T, Geiger T, Hirano T, Kishimoto T, Tran-Thi T A, Decker K, Heinrich P C
Biochemisches Institut, Universität Freiburg, Federal Republic of Germany.
Eur J Biochem. 1988 Apr 15;173(2):287-93. doi: 10.1111/j.1432-1033.1988.tb13997.x.
The regulation of the three major acute-phase proteins alpha 2-macroglobulin, cysteine proteinase inhibitor and alpha 1-antitrypsin by recombinant human interleukin-1 beta, recombinant human interleukin-6 and recombinant human tumor necrosis factor alpha was studied in rat hepatocyte primary cultures. Synthesis and secretion of the acute-phase proteins was measured after labeling with [35S]methionine and immunoprecipitation. Incubation of hepatocytes with interleukin-6 led to dose-dependent and time-dependent changes in the synthesis of the three major acute-phase proteins and albumin, similar to those occurring in vivo during experimental inflammation. alpha 2-Macroglobulin and cysteine proteinase inhibitor synthesis was induced 54-fold and 8-fold, respectively, 24 h after the addition of 100 units/ml interleukin-6. At the same time synthesis of the negative acute-phase protein albumin was reduced to 30% of controls. Half-maximal effects were achieved with 4 units interleukin-6/ml. Interleukin-1 beta had only a partial effect on the regulation of the four patients studied: only a twofold stimulation of alpha 2-macroglobulin and a 60% reduction of albumin synthesis were observed. Tumor necrosis factor alpha did not alter the synthesis of acute-phase proteins. The stimulation of alpha 2-macroglobulin and cysteine proteinase inhibitor synthesis by interleukin-6 was inhibited by interleukin-1 beta in a dose-dependent manner. In pulse-chase experiments the effect of interleukin-1 beta, interleukin-6 and tumor necrosis factor alpha on the secretion of acute-phase proteins was examined. Interleukin-6 markedly accelerated the secretion of total proteins and alpha 2-macroglobulin, whereas the secretion of cysteine proteinase inhibitor, alpha 1-antitrypsin and albumin was not affected. The inhibition of N-glycosylation by tunicamycin abolished the effect of interleukin-6 on the secretion of alpha 2-macroglobulin, indicating a possible role of interleukin-6 on N-glycosylation.
在大鼠肝细胞原代培养物中研究了重组人白细胞介素-1β、重组人白细胞介素-6和重组人肿瘤坏死因子α对三种主要急性期蛋白α2-巨球蛋白、半胱氨酸蛋白酶抑制剂和α1-抗胰蛋白酶的调节作用。用[35S]甲硫氨酸标记并进行免疫沉淀后，测定急性期蛋白的合成和分泌。用白细胞介素-6孵育肝细胞会导致三种主要急性期蛋白和白蛋白的合成出现剂量依赖性和时间依赖性变化，类似于实验性炎症期间体内发生的变化。添加100单位/毫升白细胞介素-6后24小时，α2-巨球蛋白和半胱氨酸蛋白酶抑制剂的合成分别被诱导了54倍和8倍。与此同时，负急性期蛋白白蛋白的合成降至对照组的30%。4单位白细胞介素-6/毫升可达到半数最大效应。白细胞介素-1β对所研究的四种蛋白的调节只有部分作用：仅观察到α2-巨球蛋白有两倍的刺激作用，白蛋白合成减少60%。肿瘤坏死因子α未改变急性期蛋白的合成。白细胞介素-1β以剂量依赖性方式抑制白细胞介素-6对α2-巨球蛋白和半胱氨酸蛋白酶抑制剂合成的刺激作用。在脉冲追踪实验中，研究了白细胞介素-1β、白细胞介素-6和肿瘤坏死因子α对急性期蛋白分泌的影响。白细胞介素-6显著加速了总蛋白和α2-巨球蛋白的分泌，而半胱氨酸蛋白酶抑制剂、α1-抗胰蛋白酶和白蛋白的分泌未受影响。衣霉素对N-糖基化的抑制消除了白细胞介素-6对α2-巨球蛋白分泌的影响，表明白细胞介素-6对N-糖基化可能有作用。
