RGD Reference Report - C/EBPalpha regulates hepatic transcription of hepcidin, an antimicrobial peptide and regulator of iron metabolism. Cross-talk between C/EBP pathway and iron metabolism. - Rat Genome Database

RGD Reference Report - C/EBPalpha regulates hepatic transcription of hepcidin, an antimicrobial peptide and regulator of iron metabolism. Cross-talk between C/EBP pathway and iron metabolism. - Rat Genome Database

Submit Data | Help | Video Tutorials | News | Publications | Download | REST API | Citing RGD | Contact

General

C/EBPalpha regulates hepatic transcription of hepcidin, an antimicrobial peptide and regulator of iron metabolism. Cross-talk between C/EBP pathway and iron metabolism.
Authors:	Courselaud, B Pigeon, C Inoue, Y Inoue, J Gonzalez, FJ Leroyer, P Gilot, D Boudjema, K Guguen-Guillouzo, C Brissot, P Loreal, O Ilyin, G
Citation:	Courselaud B, etal., J Biol Chem 2002 Oct 25;277(43):41163-70.
RGD ID:	727410
Pubmed:	PMID:12183449 (View Abstract at PubMed)
DOI:	DOI:10.1074/jbc.M202653200 (Journal Full-text)
Originally identified as a gene up-regulated by iron overload in mouse liver, the HEPC gene encodes hepcidin, the first mammalian liver-specific antimicrobial peptide and potential key regulator of iron metabolism. Here we demonstrate that during rat liver development, amounts of HEPC transcripts were very low in fetal liver, strongly and transiently increased shortly after birth, and reappeared in adult liver. To gain insight into mechanisms that regulate hepatic expression of hepcidin, 5'-flanking regions of human and mouse HEPC genes were isolated and analyzed by functional and DNA binding assays. Human and mouse HEPC promoter-luciferase reporter vectors exhibited strong basal activity in hepatoma HuH-7 and mouse hepatocytes, respectively, but not in non-hepatic U-2OS cells. We found that CCAAT/enhancer-binding protein alpha (C/EBPalpha) and C/EBPbeta were respectively very potent and weak activators of both human and mouse promoters. In contrast, co-expression of hepatocyte nuclear factor 4alpha (HNF4alpha) failed to induce HEPC promoter activity. By electrophoretic mobility shift assay we demonstrated that one putative C/EBP element found in the human HEPC promoter (-250/-230) predominantly bound C/EBPalpha from rat liver nuclear extracts. Hepatic deletion of the C/EBPalpha gene resulted in reduced expression of HEPC transcripts in mouse liver. In contrast, amounts of HEPC transcripts increased in liver-specific HNF4alpha-null mice. Decrease of hepcidin mRNA in mice lacking hepatic C/EBPalpha was accompanied by iron accumulation in periportal hepatocytes. Finally, iron overload led to a significant increase of C/EBPalpha protein and HEPC transcripts in mouse liver. Taken together, these data demonstrate that C/EBPalpha is likely to be a key regulator of HEPC gene transcription and provide a novel mechanism for cross-talk between the C/EBP pathway and iron metabolism.

Objects referenced in this article

Gene	Cebpa	CCAAT/enhancer binding protein alpha	Rattus norvegicus
Gene	Hamp	hepcidin antimicrobial peptide	Rattus norvegicus

Additional Information