Expression of the angiogenic protein, platelet-derived endothelial cell growth factor, in coronary atherosclerotic plaques - In vivo correlation of lesional microvessel density and constrictive vascular remodeling

Recent information indicates that platelet-derived endothelial cell growth factor (PD-ECGF), a 45-kDa angiogenic protein, is expressed in the endothel ium of various tissues and that its level of expression is correlated with the number of microvessels in human tumors. Because the formation of neoves sels is also thought to play a role in atherosclerotic vascular remodeling, we analyzed PD-ECGF expression in fresh, coronary plaque tissues obtained by directional coronary atherectomy. Specimens from 31 patients were collec ted and analyzed by reverse transcription-polymerase chain reaction, histoc hemical staining, immunohistochemistry, and in situ hybridization with the use of PD-ECGF-specific primers and probes. Lesional vascular remodeling wa s assessed by intravascular ultrasound. PD-ECGF immunoreactivity and mRNA w ere found in plaque macrophages, endothelial cells of plaque neovessels, an d stellate smooth muscle cells of 20 atherectomy specimens (64.5%). PD-ECGF immunoreactivity was correlated with the number of lesional microvessels a nd mast cells. Double-staining experiments revealed a close spatial proximi ty of PD-ECGF-positive cells and mast cells. Furthermore, the numbers of mi crovessels and mast cells were significantly higher in lesions lacking comp ensatory enlargement. The data indicate that PD-ECGF is expressed within ce lls of the atherosclerotic plaque and may be involved in driving angiogenes is in concert with mast cells.