title: A novel hemoglobin-binding peptide reduces cell-free hemoglobin in murine hemolytic anemia.
abstract: Hemolysis can saturate the hemoglobin (Hb)/heme scavenging system, resulting in increased circulating cell-free Hb (CF-Hb) in hereditary and acquired hemolytic disease. While recent studies have suggested a central role for intravascular hemolysis and CF-Hb in the development of vascular dysfunction, this concept has stimulated considerable debate. This highlights the importance of determining the contribution of CF-Hb to vascular complications associated with hemolysis. Therefore, a novel Hb-binding peptide was synthesized and linked to a small fragment of apolipoprotein E (amino acids 141-150) to facilitate endocytic clearance. Plasma clearance of hE-Hb-b10 displayed a rapid phase t(1/2) of 16 min and slow phase t(1/2) of 10 h, trafficking primarily through the liver. Peptide hE-Hb-B10 decreased CF-Hb in mice treated with phenylhydrazine, a model of acute hemolysis. Administration of hE-Hb-B10 also attenuated CF-Hb in two models of chronic hemolysis: Berkeley sickle cell disease (SS) mice and mice with severe hereditary spherocytosis (HS). The hemolytic rate was unaltered in either chronic hemolysis model, supporting the conclusion that hE-Hb-B10 promotes CF-Hb clearance without affecting erythrocyte lysis. Interestingly, hE-Hb-B10 also decreased plasma ALT activity in SS and HS mice. Although acetylcholine-mediated facialis artery vasodilation was not improved by hE-Hb-B10 treatment, the peptide shifted vascular response in favor of NO-dependent vasodilation in SS mice. Taken together, these data demonstrate that hE-Hb-B10 decreases CF-Hb with a concomitant reduction in liver injury and changes in vascular response. Therefore, hE-Hb-B10 can be used to investigate the different roles of CF-Hb in hemolytic pathology and may have therapeutic benefit in the treatment of CF-Hb-mediated tissue damage.
authors.affiliation: Department of Biophysics and Redox Biology Program, Medical College of Wisconsin, Milwaukee, WI, USA.
authors.forename: Madelyn S
authors.initials: MS
authors.lastname: Hanson
authors.forename: Hao
authors.initials: H
authors.lastname: Xu
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Flewelen
authors.forename: Sandra L
authors.initials: SL
authors.lastname: Holzhauer
authors.forename: Dawn
authors.initials: D
authors.lastname: Retherford
authors.forename: Deron W
authors.initials: DW
authors.lastname: Jones
authors.forename: Anne C
authors.initials: AC
authors.lastname: Frei
authors.forename: Kirkwood A
authors.initials: KA
authors.lastname: Pritchard
authors.forename: Cheryl A
authors.initials: CA
authors.lastname: Hillery
authors.forename: Neil
authors.initials: N
authors.lastname: Hogg
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Wandersee
mesh_terms: D000208:Acute Disease; D000743:Anemia, Hemolytic / Q000097:blood / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D000755:Anemia, Sickle Cell / Q000097:blood / Q000150:complications / Q000188:drug therapy; D000818:Animals; D001057:Apolipoproteins E / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology*; D002908:Chronic Disease; D004195:Disease Models, Animal; D004705:Endocytosis / Q000187:drug effects*; D006207:Half-Life; D006454:Hemoglobins / Q000378:metabolism*; D006461:Hemolysis; D006801:Humans; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009569:Nitric Oxide / Q000378:metabolism; D010446:Peptide Fragments / Q000097:blood / Q000494:pharmacology; D010455:Peptides / Q000097:blood / Q000494:pharmacology; D010659:Phenylhydrazines; D011485:Protein Binding; D021381:Protein Transport; D013103:Spherocytosis, Hereditary / Q000097:blood / Q000150:complications / Q000188:drug therapy; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D001057:Apolipoproteins E; D006454:Hemoglobins; D010446:Peptide Fragments; D010455:Peptides; D010659:Phenylhydrazines; D014665:Vasodilator Agents; C030299:phenylhydrazine; D009569:Nitric Oxide