Hepcidin regulation of ferroportin 1 expression in the liver and intestine of the rat

K Yeh, M Yeh, J Glass - American Journal of Physiology …, 2004 - journals.physiology.org
K Yeh, M Yeh, J Glass
American Journal of Physiology-Gastrointestinal and Liver …, 2004journals.physiology.org
Hepcidin has been implicated as the iron stores regulator: a hepatic signaling molecule that
regulates intestinal iron absorption by undefined mechanisms. The possibility that hepcidin
regulates the expression of ferroportin 1 (FPT1), the basolateral iron transporter, was
examined in rats after administration of LPS, an iron chelator, or His-tagged recombinant
hepcidin (His-rHepc). In the liver, LPS stimulated a biphasic increase of hepcidin mRNA with
peaks of mRNA at 6 and 36 h. Concurrently, hepatic FPT1 mRNA expression decreased to …
Hepcidin has been implicated as the iron stores regulator: a hepatic signaling molecule that regulates intestinal iron absorption by undefined mechanisms. The possibility that hepcidin regulates the expression of ferroportin 1 (FPT1), the basolateral iron transporter, was examined in rats after administration of LPS, an iron chelator, or His-tagged recombinant hepcidin (His-rHepc). In the liver, LPS stimulated a biphasic increase of hepcidin mRNA with peaks of mRNA at 6 and 36 h. Concurrently, hepatic FPT1 mRNA expression decreased to minimal level at 6 h and then increased with a peak at 24–36 h. LPS also induced biphasic changes in intestinal FPT1 mRNA expression, with decreased levels at 6 h and increased expression at 48 h. Whereas the initial decrease of FPT1 coincides with an LPS-induced decrease in serum iron, both intestinal and hepatic FPT1 expression recovered, whereas serum iron concentration continued to decrease for at least 24 h. Dietary iron ingestion increased intestinal ferritin protein production but did not reduce intestinal FPT1 mRNA expression. The iron chelator pyrrolidinedithiocarbamate (PDTC) stimulated hepatic hepcidin without suppressing intestinal FPT1 expression. In PDTC-treated rats, LPS stimulated no additional hepatic hepcidin expression but did increase intestinal FPT1 expression. Administration of HisrHepc induced significant reduction of intestinal FPT1 expression. Taken together, these data suggest that hepcidin mediates LPS-induced downregulation of intestinal FPT1 expression and that the hepcidin signaling pathway involves a PDTC-sensitive step.
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