Hepatocyte nuclear factor-4alpha and -1 small interfering RNA inhibits hepatocyte differentiation induced by extracellular matrix.
Liver-specific genes and hepatocyte nuclear factor (HNF)-4alpha and -1 are coordinately regulated by extracellular matrix (ECM). However, still are unclear interactions between liver-specific genes and these liver-enriched transcription factors in the mechanism of hepatocyte differentiation regulated by ECM. To elucidate the relationship, we used small interfering RNA (siRNA), which obtains strong and specific knockdown of gene expression in cell culture. Treatment with siHNF-4alpha and siHNF-1 declined the expression levels for HNF-4alpha mRNA and HNF-1 mRNA in primary rat hepatocytes, respectively. The mRNA expressions of albumin, transthyretin, and apolipoproteins that were up-regulated in hepatocytes cultured on a basement membrane matrix, Engelbreth-Holm-Swarm (EHS) gel, were decreased in the presence of siHNF-4alpha or siHNF-1. Moreover, siHNF-4alpha and siHNF-1 did not affect the morphology and actin assembly of hepatocytes. These findings demonstrated that HNF-4alpha and HNF-1 directly regulate liver-specific gene expression and might be downstream of cytoskeletal organization in the mechanism by which the differentiated phenotype of hepatocytes is regulated by EHS gel.
Kimata
Takayuki
T
Department of Gastroenterology, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan.
Nagaki
Masahito
M
Tsukada
Yoshihiko
Y
Ogiso
Tomio
T
Moriwaki
Hisataka
H