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This Article Full Text Full Text (PDF) All Versions of this Article: 287/4/H1875    most recent 00164.2004v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by D'Agnillo, F. Search for Related Content PubMed PubMed Citation Articles by D'Agnillo, F.

Redox active hemoglobin enhances lipopolysaccharide-induced injury to cultured bovine endothelial cells

Laboratory of Biochemistry and Vascular Biology, Division of Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland 20892

Submitted 17 February 2004 ; accepted in final form 16 June 2004

The interaction of cell-free hemoglobin with lipopolysaccharide (LPS) is thought to aggravate the pathophysiology of sepsis and/or septic shock. This study examines the possible modulatory role of cell-free hemoglobin on LPS-induced apoptosis of cultured bovine aortic endothelial cells. Experiments were performed with or without fetal bovine serum, a source of LPS-binding protein and soluble CD14. In the absence of serum, LPS alone or coincubated with purified bovine hemoglobin (BvHb), human hemoglobin (Hb), or -cross-linked Hb (Hb) did not induce apoptosis. In the presence of serum, LPS induced significant apoptosis. LPS combined with BvHb, Hb, or Hb produced the same extent of apoptosis as LPS alone. To examine whether the H₂O₂-driven redox activity of hemoglobin alters LPS-induced apoptosis, glucose oxidase was added to the system to generate a subtoxic flux of H₂O₂. The combined treatment of LPS, glucose oxidase, and BvHb, Hb, or Hb enhanced apoptosis compared with LPS alone. These findings support a possible mechanism whereby the redox cycling of hemoglobin, and not its direct interaction with LPS, contributes to the hemoglobin-mediated enhancement of LPS-related pathophysiology.

apoptosis; ferryl hemoglobin; hydrogen peroxide; glucose oxidase