AFAR Southeast Affiliate at Emory University

Effects of Age on Endothelial Progenitor Cell Mobilization in Humans

1) Please give a brief summary of your AFAR research project.

Coronary atherosclerosis is a leading cause of aging-related death in the world. It is due to injury of the wall of the arteries feeding the heart, resulting in inflammation and lumen obstruction, which leads to heart damage and death. Naturally occurring stem cells circulating in the bloodstream can regenerate and rejuvenate the injured artery, preventing inflammation and arterial obstruction. Circulating stem cell activity, however, diminishes with age. We will examine circulating stem cells in young and older patients after arterial injury caused by a common procedure, coronary balloon angioplasty.

2) What problems are you addressing and what specific questions will your research seek to answer?

We wish understand why a diminishing circulating stem cell response to angioplasty is seen with aging. More specifically, we hope to understand whether reduced circulating stem cell activity is due to reduced numbers of cells released from the bone marrow, or whether it is due to a decreased ability of individual cells to grow and function. We also hope to understand what chemical factors signal the cells that arterial injury has taken place.

3) What aspects of your project are most interesting from a scientific point of view?

Stem cell activity and its role in coronary heart disease is poorly understood, but emerging evidence suggests an important role. It may be that stem cell defects are the missing "risk factor" for coronary heart disease, explaining why so many otherwise seemingly healthy people are afflicted.

4) What are the implications of your research for age-related diseases and disorders?

The role of stem cells in aging-related diseases is just beginning to be understood. Diminishing stem cell number, function or signaling as a cause of disease represents a new paradigm in aging-related disorders. Aging itself may not simply represent a gradual accumulation of disease, but may also be due to a decline in the bodies ability to repair itself. Such a discovery could potentially broaden the targets and promise of stem cell therapy.