部分肝切除术后大鼠肝脏中CCAAT/增强子结合蛋白α（C/EBPα）和C/EBPβ的表达变化，但醋酸环丙孕酮治疗后未出现这种变化。

Changes in expression of CCAAT/enhancer binding protein alpha (C/EBP alpha) and C/EBP beta in rat liver after partial hepatectomy but not after treatment with cyproterone acetate.

作者信息

Skrtic S, Ekberg S, Wallenius V, Enerbäck S, Hedin L, Jansson J O

机构信息

Research Center for Endocrinology and Metabolism, Sahlgrenska University Hospital, University of Göteborg, Sweden.

出版信息

J Hepatol. 1997 Nov;27(5):903-11. doi: 10.1016/s0168-8278(97)80329-7.

DOI:10.1016/s0168-8278(97)80329-7

PMID:9382979

Abstract

BACKGROUND/AIMS: The proliferation rate of adult rat liver is normally very low. It is markedly enhanced during compensatory regeneration, e.g. after partial hepatectomy, or after administration of certain growth promoters, e.g. cyproterone acetate. These two types of liver cell proliferation appear to differ, since the expression of immediate early genes is induced during compensatory regeneration but not after cyproterone acetate treatment. The transcription factor C/EBP alpha, which has been associated with hepatocyte differentiation and growth arrest, is suppressed during compensatory regeneration. In contrast, C/EBP beta, associated with acute phase reaction, is increased during regeneration. We have investigated the effects of the liver growth promoter cyproterone acetate on the hepatic expression of C/EBP alpha and C/EBP beta.

METHODS

Adult male rats received either cyproterone acetate treatment or were subjected to partial hepatectomy. Livers were obtained at different time intervals for measurement of C/EBP alpha and C/EBP beta mRNA with solution hybridization/RNAse protection assay, and C/EBP alpha and C/EBP beta content with immunoblotting.

RESULTS

The levels of both C/EBP alpha and C/EBP beta mRNA and the corresponding immunoreactivities were unchanged 2-48 h after injection of cyproterone acetate. The levels of C/EBP alpha mRNA and immunoreactivity were significantly suppressed 10-18 h and 18-26 h after partial hepatectomy, respectively. The levels of C/EBP beta mRNA and immunoreactivity were enhanced during compensatory regeneration 2 h after partial hepatectomy.

CONCLUSIONS

Liver cell proliferation during regeneration, but not in response to cyproterone acetate treatment, is associated with changes in C/EBP alpha and C/EBP beta expression. This further supports the notion that changes in expression of transcription factors during liver growth in vivo are dependent on the growth inducer.

摘要

背景/目的：成年大鼠肝脏的增殖速率通常非常低。在代偿性再生过程中，例如部分肝切除术后，或给予某些生长促进剂（如醋酸环丙孕酮）后，其增殖速率会显著提高。这两种类型的肝细胞增殖似乎有所不同，因为即时早期基因的表达在代偿性再生过程中被诱导，但在醋酸环丙孕酮处理后则不会。与肝细胞分化和生长停滞相关的转录因子C/EBPα在代偿性再生过程中受到抑制。相比之下，与急性期反应相关的C/EBPβ在再生过程中增加。我们研究了肝脏生长促进剂醋酸环丙孕酮对肝脏中C/EBPα和C/EBPβ表达的影响。