LEUKEMIA INHIBITORY FACTOR EXPRESSION IN HUMAN CAROTID PLAQUES - POSSIBLE MECHANISM FOR INHIBITION OF LARGE VESSEL ENDOTHELIAL REGROWTH

One common feature of atherosclerotic plaques is the denudation of the endothelium covering the plaque and subsequent failure of endothelial regrowth in contrast to a marked proliferation of neocapillaries aris ing from the vasa vasorum within the medial wall. Previous studies in vitro have demonstrated the ability of leukemia inhibitory factor (LIF ) to potently inhibit aortic endothelial cell growth while only slight ly inhibiting the growth of adrenal cortex capillary endothelial cells . This selective effect of LIF on endothelial cells from different sou rces suggests that it may play a role in the failure of endothelial re growth in atherosclerosis. Sections of human carotid endartectomy samp les were examined by in situ hybridization for LIF mRNA expression. In one-third of the samples (4/12) examined, cells within the atheroscle rotic plaque exhibited LIF expression. Immunohistochemistry of serial sections suggested that the LIF-positive cells were activated macropha ges. These results suggest that LIF may play a role in the pathogenesi s of atherosclerosis, particularly the denudation of the large vessel endothelium.