Hemoglobin-based oxygen carrier induces hepatic heme oxygenase 1 expression in Kupffer cells.
BACKGROUND
Kupffer cells (liver macrophages) are a key initiator of inflammation following hepatic insults such as infection, ischemia/reperfusion, and rejection. Heme oxygenase 1 (HO-1) is protective against inflammatory injury. A hemoglobin-based oxygen carrier (HBOC) has been shown to prevent organ inflammation from hemorrhagic shock as well as induce HO-1 at the cellular level. Therefore, we hypothesize that HBOC can induce Kupffer cell HO-1 production.


METHODS
Mice administered 20% blood volume HBOC or saline intravenously were sacrificed at 0, 12, 24, 48 hours (n = 4-6/group). Hepatic protein underwent Western blotting for HO-1 and heat shock protein 72. Hepatic frozen sections underwent immunofluorescent staining for HO-1/CD68.


RESULTS
Following HBOC injection, hepatic HO-1 fold change peaked at 12 hours (7.3 +/- 0.8) (p < .01), remained increased at 24 hours (4.7 +/- 0.4) (p < .01), and returned to baseline by 48 hours. HSP72 expression was unaffected in all groups. Twleve-hour liver section immunostaining confirmed significant induction of HO-1 by HBOC. Double staining for HO-1 and CD68 identified Kupffer cells as the majority of cells expressing HO-1.


CONCLUSIONS
HBOC induces hepatic HO-1 expression in Kupffer cells without heat shock protein response. These data provide the basis for further investigation into a clinical therapy to induce Kupffer cell HO-1 expression with the goal of attenuating the hepatic immunoresponse to various insults.
Babu
Ashok N
AN
Health Sciences Center, University of Colorado at Denver, Denver, Colorado, USA.
Damle
Sagar S
SS
Moore
Ernest E
EE
Ao
Lihua
L
Song
Yong
Y
Johnson
Jeffrey L
JL
Weyant
Michael
M
Banerjee
Anirban
A
Meng
Xianzhong
X
Fullerton
David A
DA
D000818:Animals; D001802:Blood Substitutes / Q000494:pharmacology*; D004789:Enzyme Activation; D005455:Fluorescent Antibody Technique; D050884:HSP72 Heat-Shock Proteins / Q000378:metabolism; D051547:Heme Oxygenase-1 / Q000378:metabolism*; D007728:Kupffer Cells / Q000187:drug effects* / Q000201:enzymology*; D051379:Mice; D008810:Mice, Inbred C57BL; D010100:Oxygen / Q000378:metabolism; D010108:Oxyhemoglobins / Q000494:pharmacology*
D001802:Blood Substitutes; D050884:HSP72 Heat-Shock Proteins; D010108:Oxyhemoglobins; D051547:Heme Oxygenase-1; D010100:Oxygen