Figure 5: BLVRB May Be Associated With Heme-Catabolism in Plaques via HMOX1

Heme oxygenase 1 (HMOX1) mRNA was highly up-regulated in Biobank of Karolinska Endarterectomies microarrays comparing plaques and normal arteries and strongly correlated to that of BLVRB. Plots showing log2 mean ± SD and Spearman correlation (A). Induction of HMOX1 and correlation with BLVRB could be verified on the protein level by LC-MS/MS from plaques compared with adjacent tissue (B). No staining for HMOX1 was observed in the normal carotid artery, whereas weak signal for BLVRB could occasionally be seen in adventitia. Using consecutive sections of plaques, HMOX1 was localized to the sites of hemorrhage with infiltrated erythrocytes, where it overlapped with BLVRB and Perls blue staining for iron deposits (C, enlarged insets). The correlation between BLVRB and HMOX1 content and intraplaque hemorrhage was also assessed quantitatively, using histological staining on TMA constructed from 106 plaques (D, plot to the right). Abbreviations as in Figures 1, 2, and 3.