Analysis of local gene expression in human atherosclerotic plaques by in situ hybridization

In situ hybridization is an invaluable tool for the examination of gene expression in human atherosclerotic plaques, and therefore is useful for research into the underlying mechanisms of atherogenesis. Information obtained using this technique includes determining not only the presence or absence of a specific mRNA in a tissue sample, but also the type of cell expressing the gene of interest. Cells containing platelet-derived growth factor (PDGF) mRNA were identified in carotid endarterectomy specimens by in situ hybridization. Mesenchymal-appearing intimal cells, the major cell type containing PDGF mRNAs and expressing PDGF, were often found associated with focal regions of organizing thrombus. It is suggested that organization of thrombi resulting from plaque rupture or intraplaque hemorrhage of the vasa vasorum may contribute to the episodic growth of the atherosclerotic plaque through an influence on these cells.