title: Soluble transferrin receptor-1 levels in mice do not affect iron absorption.
abstract: Soluble transferrin receptor-1 (sTfR1) concentrations are increased in the plasma under two conditions that are associated with increased iron absorption, i.e. iron deficiency and increased erythropoiesis. To determine the possible role of sTfR1 as a signaling mechanism for iron absorption, a hydrodynamic gene transfer technique was established to express transfected plasmid constructs of human sTfR1 (hsTfR1) and murine sTfR1 (msTfR1) from the livers of C57BL/6 mice. Iron absorption, serum iron levels and hepcidin expression were then measured. The hydrodynamic gene transfer technique proved to be an effective approach to achieving sustained expression of sTfR1 in mice. Although expression of high levels of sTfR1 significantly increased serum iron levels, repeated experiments showed that neither hsTfR1 nor msTfR1 had any effect on iron absorption or hepcidin mRNA expression levels. Thus, despite its attractiveness as a potential modifier of iron absorption, sTfR1 levels do not exert a regulatory effect on iron absorption.
authors.affiliation: Department of Molecular and Experimental Medicine, Scripps Research Institute, MEM-215, La Jolla, CA 92037, USA.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Flanagan
authors.forename: Hongfan
authors.initials: H
authors.lastname: Peng
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Terri
authors.initials: T
authors.lastname: Gelbart
authors.forename: Pauline
authors.initials: P
authors.lastname: Lee
authors.forename: Barbra
authors.initials: B
authors.lastname: Johnson Sasu
authors.forename: Ernest
authors.initials: E
authors.lastname: Beutler
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000097:blood* / Q000235:genetics / Q000494:pharmacology; D005260:Female; D018014:Gene Transfer Techniques; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects*; D007501:Iron / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000032:analysis; D011990:Receptors, Transferrin / Q000097:blood* / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction; D012995:Solubility
chemical_list: D015703:Antigens, CD; C068126:CD71 antigen; D012333:RNA, Messenger; D011990:Receptors, Transferrin; C480029:Tfrc protein, mouse; D007501:Iron