A method to isolate morphologically distinct clones of smooth muscle cells from human saphenous vein.

The monoclonal theory of atherosclerosis postulates that a certain subpopulation of vascular smooth muscle cells (VSMC) is selectively expanded in response to pathological stimuli thereby contributing to the formation of atherosclerotic plaques. VSMC cloning experiments will be important in characterizing the phenotypic composition of VSMC in atherosclerotic plaques. However, the difficulty in cloning human VSMC is well recognized. Here a technique is described that produced multiple clones from human saphenous vein. The clones could be divided into two categories based on their distinctly different morphology: (1) spindle-shaped; and, (2) epithelioid-shaped. Each clone expressed smooth muscle-a-actin and calponin, two smooth muscle-specific differentiation markers. The clonal study presented here reports for the first time that phenotypically heterogeneous smooth muscle cells coexist within human saphenous veins.