Differential expression genes analyzed by cDNA array in the regulation of rat hepatic fibrogenesis.
OBJECTIVE
To analyze the gene expression pattern in rat hepatic fibrogenesis and further assess the role of some key genes during the pathological process.


METHODS
Hepatic fibrosis was induced by intraperitoneal injection of dimethylnitrosamine or carbon tetrachloride (CCl(4)) injection subcutaneously in rats, and identification of the hepatic fibrosis related genes with cDNA microarray was performed. After some key genes up-regulated during the development of hepatic fibrosis were screened and confirmed, their effects on the function of the activated rat hepatic stellate cells (HSC) were assessed using the small interfering RNA (siRNA) technique.


RESULTS
Using an Atlas rat cDNA array, a number of differentially expressed genes in fibrotic liver tissues were identified compared with non-diseased control. A total of 15 genes predominantly associated with the mitogen-activated protein kinase (MAPK) signal transduction pathway were upregulated in the fibrotic liver. Immunohistochemical study revealed that the expressions of both extracellular signal-regulated kinases (ERK) and ribosomal protein S6 kinase (RSK), two of the key genes in the MAPK pathway, were remarkably induced, which was closely correlated to that of collagen types I and III during the development of hepatic fibrosis. Transfection of siRNA targeting ERK1 mRNA (siERK1) into HSC led to a 66% and 72% reduction of ERK1 mRNA and protein expression, respectively. Furthermore, siERK1 exerted the inhibition of the proliferation of HSC, accompanied by the induction of HSC apoptosis and reduction of collagen types I and III. In addition, siERK1 abolished the effect of platelet-derived growth factor-BB on the proliferation of HSC.


CONCLUSIONS
The present study provided strong evidence for the participation of the MAPK pathway in the pathogenesis of hepatic fibrosis. Selective targeting of ERK1 inhibitors to HSC might present as a novel strategy for the treatment of hepatic fibrosis.
Qiang
Hui
H
Department of Gastroenterology, Changzheng Hospital, Second Military Medical University, Shanghai, Shanghai, China.
Lin
Yong
Y
Zhang
Xin
X
Zeng
Xin
X
Shi
Jian
J
Chen
Yue-Xiang
YX
Yang
Miao-Fang
MF
Han
Ze-Guang
ZG
Xie
Wei-Fen
WF
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D003094:Collagen / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics; D015870:Gene Expression; D020869:Gene Expression Profiling; D008099:Liver / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D008106:Liver Cirrhosis, Experimental / Q000235:genetics*; D020935:MAP Kinase Signaling System; D008297:Male; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000494:pharmacology; D020411:Oligonucleotide Array Sequence Analysis; D034622:RNA Interference; D051381:Rats; D017207:Rats, Sprague-Dawley; D019893:Ribosomal Protein S6 Kinases / Q000235:genetics; D014158:Transcription, Genetic
D003094:Collagen; D019893:Ribosomal Protein S6 Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D048052:Mitogen-Activated Protein Kinase 3