Neutrophil Granulocytes Are the Only Source of MPO in Injured Liver.
Ahmad Amanzada, Ihtzaz Ahmed Malik, Sadaf Sultan, Giuliano Ramadori. University of Medicine, Goettingen, Germany
Background: Myeloperoxidase (MPO) is involved in acute and chronic inflammatory diseases. The source of MPO in acute liver diseases is still a matter of debate.
Design: Therefore, we anlaysed MPO-gene expression on sections from normal and acutely damaged [carbon tetrachloride- (CCl4) or Whole Liver g-Irradiation] rat liver by immunohistochemistry, real time PCR and Western blot analysis of total RNA and protein. Also total RNA and protein from isolated Kupffer cells (KC), hepatic stellate cells, Hepatocytes, endothelial cells and neutrophil granulocytes (NG) was analysed by real time PCR and Western blot, respectively. Sections of acutely injured human liver were prepared for MPO and CD-68 immunofluorescence double staining.
Results: In normal rat liver MPO was detected immunohistochemically and by immunofluorescence double staining only in single NG. No MPO was detected in isolated parenchymal and non-parenchymal cell populations of the normal rat liver. In acutely damaged rat liver mRNA of MPO increased 2,8-fold at 24 hr after administration of CCl4 and 3,3-fold at 3 hr after g-Irradiation. In acutely damaged rat and human livers MPO was detected immunhistochemically and by immunofluorescence double staining only in NGs. NG identity was confirmed by immmunostaining of neutrophil elastase. Furhtermore, there was no detection of MPO in ED1/CD-68 positive Cells either.
Conclusions: Our results demonstrate that, in contrast to earlier reports (e.g. Hepatology 2009; 50: 1484-1493) expression of MPO in damaged rat and human liver seems to be due to recruited NGs.
Category: Liver & Pancreas
Wednesday, March 2, 2011 9:30 AM
Poster Session V # 185, Wednesday Morning