Beauchamp R D, Papaconstantinou J, Henderson A M, Sheng H M, Townsend C M, Thompson J C
Department of Surgery, University of Texas Medical Branch, Galveston 77555-0533.
Surgery. 1994 Aug;116(2):367-76; discussion 376-7.
The hepatic acute-phase response is the result of reprogramming of gene expression in the liver. Similar acute-phase responses occur in regenerating liver after partial hepatectomy and are preceded by increases in the expression of a set of transcriptional regulatory proteins that are encoded by "immediate-early" genes. The purpose of this study was to determine whether acute systemic inflammation after lipopolysaccharide injection induces hepatic immediate-early genes that are induced by partial hepatectomy.
Two- to 4-month-old Balb/c mice received intraperitoneal Escherichia coli lipopolysaccharide (0111:B4; 100 micrograms), and total liver RNA, nuclear protein extracts, or total liver protein lysates were obtained at 0, 1, 3, 12, and 24 hours. RNA blot hybridization analysis was used to determine steady-state messenger RNA levels for c-jun, jun-B, jun-D, c-fos, fos-B, fra-1, nup475, and zif268. Specific nuclear protein-binding activity was determined by gel mobility shift assay. The protein c-Jun was detected by antibody-blocking experiments, and Jun-B was detected by gel supershift assay of the activating protein (AP-1) complex. Steady-state Jun-B levels were determined by immunoblot analysis.
Intraperitoneal injection of lipopolysaccharide is followed by induction (from fivefold to 13-fold) of c-jun, jun-B, c-fos, zif268, and nup475 messenger RNAs in the liver. Lipopolysaccharide induced increases in AP-1 and Zif268 consensus DNA-binding activity in mouse liver. The proteins c-Jun and Jun-B are detected in the AP-1 complex after administration of lipopolysaccharide.
The induction of hepatic immediate-early genes after lipopolysaccharide is similar to that that follows partial hepatectomy. These transcription factors likely have important roles in the reprogramming of gene expression that leads to the acute-phase response.
肝脏急性期反应是肝脏中基因表达重编程的结果。在部分肝切除术后的再生肝脏中也会出现类似的急性期反应，且在此之前一组由“即刻早期”基因编码的转录调节蛋白的表达会增加。本研究的目的是确定脂多糖注射后急性全身炎症是否会诱导部分肝切除所诱导的肝脏即刻早期基因。
2至4月龄的Balb/c小鼠腹腔注射大肠杆菌脂多糖（0111:B4；100微克），并在0、1、3、12和24小时获取肝脏总RNA、核蛋白提取物或肝脏总蛋白裂解物。采用RNA印迹杂交分析来测定c-jun、jun-B、jun-D、c-fos、fos-B、fra-1、nup475和zif268的稳态信使RNA水平。通过凝胶迁移率变动分析来测定特异性核蛋白结合活性。通过抗体阻断实验检测蛋白c-Jun，通过激活蛋白（AP-1）复合物的凝胶超迁移分析检测Jun-B。通过免疫印迹分析测定稳态Jun-B水平。
腹腔注射脂多糖后，肝脏中c-jun、jun-B、c-fos、zif268和nup-475信使RNA被诱导（增加5至13倍）。脂多糖诱导小鼠肝脏中AP-1和Zif268共有DNA结合活性增加。给予脂多糖后，在AP-1复合物中检测到蛋白c-Jun和Jun-B。
脂多糖注射后肝脏即刻早期基因的诱导与部分肝切除术后相似。这些转录因子可能在导致急性期反应的基因表达重编程中发挥重要作用。
