The Role of CD 34 Hematopoietic Progenitor Cells, Macrophages, and Smooth Muscle Cells in Human Coronary Artery Atherogenesis

BACKGROUND: Atherosclerosis is a widespread and devastating disease and one of the leading causes of death worldwide. So much is there to understand about atherosclerosis. And although a lot is already discovered, yet most of the studies are performed in cell cultures and animal models. Recent technologies for genetic engineering and imaging are mainly performed on animal models, with few studies in human tissues. A better understanding of their role is required. AIM: We aim to study the expression of CD 34 hematopoietic progenitor stem cell, CD 68 macrophages, and smooth muscle actin (SMA)-positive smooth muscle cells (SMCs) in the human coronary arteries and correlate their differential expression with the atherosclerosis progression. RESULTS: CD 68 and CD 34 expression increase as the atherosclerotic process proceeds from early atheroma to advanced atheroma and start to decrease as the process proceeds to fibroatheroma with a significant p < 0.001. Conversely, SMA expression decreases as the atherosclerotic process progresses with a significant p < 0.001. CONCLUSION: CD34 progenitor cells in conjunction with CD 68 macrophages have a major role in the development of atherosclerosis, whereas the SMCs are minimal in the early stages and reach their maximal levels during the stage of fibroatheroma.