title: Detection of serum hepcidin in renal failure and inflammation by using ProteinChip System.
abstract: Hepcidin, a key regulator of iron metabolism, is expressed in the liver, distributed in blood, and excreted in urine. However, to date, no reliable and practical method for measuring the bioactive form of hepcidin in serum has been developed. Here, we used surface-enhanced laser desorption ionization time of flight mass spectrometry (SELDI-TOF MS) to analyze the distinctive serum proteomic patterns of patients receiving hemodialysis. In the range of 1000 to 15,000 m/z, we found 3 peptides at 2192, 2789, and 2851 m/z that showed a significant correlation with the serum ferritin levels. The molecular sizes of peptides at 2192 and 2789 m/z matched with the reported sizes of hepcidin-20 and -25, respectively, and the serum peptide at 2789 m/z was identified as hepcidin-25 by collision-induced dissociation tandem MS. By using SELDI-TOF MS, we developed a semiquantitative assay for hepcidin-25. In this assay, the level of serum hepcidin-25 correlated well with levels of serum ferritin and serum interleukin-6. Hepcidin-25 was found to accumulate in the serum of patients receiving hemodialysis; this could contribute to the pathogenesis of renal anemia by decreasing the available iron for hematopoiesis. Thus, SELDI-TOF MS would be a clinically useful tool to detect and semiquantify bioactive hepcidin in serum.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Kanazawa Medical University, Kahoku, Ishikawa 920-0293, Japan. tomosugi@kanazawa-med.ac.jp
authors.forename: Naohisa
authors.initials: N
authors.lastname: Tomosugi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawabata
authors.forename: Rumi
authors.initials: R
authors.lastname: Wakatabe
authors.forename: Masato
authors.initials: M
authors.lastname: Higuchi
authors.forename: Hideki
authors.initials: H
authors.lastname: Yamaya
authors.forename: Hisanori
authors.initials: H
authors.lastname: Umehara
authors.forename: Isao
authors.initials: I
authors.lastname: Ishikawa
mesh_terms: D000740:Anemia / Q000097:blood* / Q000209:etiology / Q000652:urine; D023181:Antimicrobial Cationic Peptides / Q000097:blood* / Q000652:urine; D005260:Female; D005293:Ferritins / Q000097:blood; D006410:Hematopoiesis; D064451:Hepcidins; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000150:complications / Q000652:urine; D015850:Interleukin-6 / Q000097:blood; D007501:Iron / Q000378:metabolism; D008297:Male; D040081:Protein Array Analysis; D040901:Proteomics / Q000379:methods; D006435:Renal Dialysis / Q000009:adverse effects; D051437:Renal Insufficiency / Q000097:blood* / Q000150:complications / Q000628:therapy / Q000652:urine; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
chemical_list: D023181:Antimicrobial Cationic Peptides; C578702:HAMP protein, human; D064451:Hepcidins; D015850:Interleukin-6; D005293:Ferritins; D007501:Iron