NF-kappaB activates fibronectin gene expression in rat hepatocytes.
Fibronectin (FN) plays a role in various biological processes such as fibrosis and tumor metastasis. In this study, we investigated the regulation of FN gene expression by NF-kappaB transcription factor. Transient expression of NF-kappaB p65 increased FN promoter activity in rat hepatocytes. Deletion analysis of FN promoter localized the NF-kappaB-responsive region at the position between -1214 and -1126. Mutations in a putative NF-kappaB element (5(')-GAGAATTTCC-3(')) at -1180 blocked most of the p65-induced promoter activity. Electromobility shift assays showed that the expression of p65 induced the binding of the p65/p65 homodimer to the NF-kappaB site at -1180. Stably p65-expressing cells showed increase of promoter activity, FN protein, and its mRNA levels over control cells. Furthermore, treatment of cells with interleukin-1beta, a NF-kappaB-stimulating cytokine, also increased promoter activity, FN production, and mRNA levels. These results show that NF-kappaB activates FN gene expression by binding to the responsive element at -1180 as the p65/p65 homodimer in rat hepatocytes.
Lee
Byung-Heon
BH
Department of Biochemistry, School of Medicine, Dongguk University, 780-714, Kyungju, Republic of Korea.
Park
Seung-Yoon
SY
Kang
Kae-Bok
KB
Park
Rang-Wook
RW
Kim
In-San
IS
D000818:Animals; D001665:Binding Sites; D015152:Blotting, Northern; D015153:Blotting, Western; D002478:Cells, Cultured; D005353:Fibronectins / Q000096:biosynthesis*; D017353:Gene Deletion; D005786:Gene Expression Regulation; D022781:Hepatocytes / Q000378:metabolism*; D007375:Interleukin-1 / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008156:Luciferases / Q000378:metabolism; D009154:Mutation; D016328:NF-kappa B / Q000378:metabolism / Q000502:physiology*; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D051996:Transcription Factor RelA; D014162:Transfection
D005353:Fibronectins; D007375:Interleukin-1; D016328:NF-kappa B; D012333:RNA, Messenger; D051996:Transcription Factor RelA; D008156:Luciferases