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TMPRSS6 rs855791 modulates hepcidin transcription in vitro and serum hepcidin levels in normal individuals. Blood. 2011 Aug 26; Authors: Nai A, Pagani A, Silvestri L, Campostrini N, Corbella M, Girelli D, Traglia M, Toniolo D, Camaschella C Abstract
The iron hormone hepcidin is inhibited by matriptase-2, a liver serine-protease encoded by TMPRSS6 gene. Cleaving the BMP-coreceptor hemojuvelin, matriptase-2 impairs the BMP/SMAD signaling pathway, downregulates hepcidin and facilitates iron absorption. TMPRSS6 inactivation causes iron-deficiency-anemia refractory to iron administration both in humans and mice. Genome wide association studies have shown that the SNP rs855791, which causes the matriptase-2 V736A amino acid substitution, is associated with variations of serum iron, transferrin saturation, hemoglobin and erythrocyte traits. Here we show that in vitro matriptase-2 736(A) inhibits hepcidin more efficiently than 736(V). Moreover, in a genotyped population, after exclusion of samples with iron deficiency and inflammation, hepcidin, hepcidin/transferrin saturation and hepcidin/ferritin ratios were significantly lower and iron parameters were consistently higher in homozygotes 736(A) than in 736(V). Our results indicate that rs855791 is a TMPRSS6 functional variant and strengthen that even a partial inability to modulate hepcidin influences iron parameters and indirectly erythropoiesis.
PMID: 21873547 [PubMed - as supplied by publisher] Read more |
