Abstract 16886: First Quantification of Intestinal-apoB48 and Hepatic-apoB100 Particles in Human Atherosclerotic Plaque by Dual Immunofluorescence Staining
Introduction: ApoB particles are atherogenic. We have previously demonstrated the presence and different localization of intestinal apoB48 and hepatic apoB100 particles in human atherosclerotic plaques with conventional immunoperoxidase (IP) staining and single and dual immunofluorescence (DS-IF). Relative quantification of apoB100 and apoB48 in plaque has not previously been performed.
Methods: DS-IF for apoB100 and apoB48 was performed on 4 human carotid plaques from the lesion and proximal and distal regions. Two proximal (A), 4 mid- (B) and 8 distal (C) sections were stained and the area of apoB48 and apoB100 positive regions was quantified. A commercial rabbit polyclonal antibody was utilized for apoB100, while a murine monoclonal antibody (4C8) was utilized for apoB48. These antibodies bind to sites on the respective protein's C-terminal. In apoB100, the apoB48 binding site is conformationally hidden, preventing cross-reaction. We have previously demonstrated this specificity in hepatic and intestinal tissues.
Results: Compared to apoB100, apoB48-positive area was significantly larger in proximal, mid and distal sections (70% vs 5%, 53.4% vs 16.2% and 55% vs 9.3%, respectively; p<0.001 for all) (Figure).
Conclusion: In our study, apoB48-containing intestinal particles occupied significantly larger area of human carotid atherosclerotic plaques, compared to hepatic apoB100.
- © 2010 by American Heart Association, Inc.