CELL-PROLIFERATION AND COLLAGEN-SYNTHESIS ARE 2 INDEPENDENT EVENTS INHUMAN ATHEROSCLEROTIC PLAQUES

We have used a double-immunolabelling technique on human carotid ather osclerotic plaques to measure cell proliferation and type-I collagen g ene expression, using antibodies to proliferating cell nuclear antigen (PCNA) and type-I procollagen protein, respectively. Although cell pr oliferative activity and type-I collagen gene expression can occur sim ultaneously in the same cell, this is a rare event, and the vast major ity of collagen-producing cells do not show proliferative activity. Th ese two processes also tend to occur in separate locations, although t hey can coexist in certain regions of the plaque. This disparate locat ion of these two important modes of plaque growth suggests that cell p roliferation and collagen gene expression may be under separate biolog ical controls during the development and evolution of human atheroscle rosis.