The role of stem cells in anti-aging medicine.

Aging is the result of two overlapping processes, "intrinsic" and "extrinsic." Intrinsic structural changes occur as a consequence of physiologic aging and are genetically determined; extrinsic relates to exposure to harmful events and habits, like smoking, bad diet, alcohol consumption, lack of sleep, stress, sun exposure, environmental pollution, etc. Aging may be decelerated by improving bad habits or treating signs of aging with various esthetic methods, food supplements, and antioxidants. It is believed that we cannot stop aging entirely due to the intrinsic part, which leads to irreversible cell damage, as well as tissue and organ damage due to their limited ability to regenerate. Stem cells and their ability to exhibit telomerase activity, to self-renew, and to differentiate into all three embryonic tissues challenges aging as a process, which is not inevitable and can even possibly be reversed. Stem cells can promote regeneration of aged tissues and organs by replacing apoptotic and necrotic cells with healthy ones. In addition, they can have antiinflammatory and antiapoptotic properties by paracrine-secreting growth factors and cytokines on the site of administration. Autologous adipose-derived stem cells are the most promising because they can be easily harvested in huge numbers with minimally invasive liposuction and, as such, represent a powerful tool in anti-aging and regenerative medicine. In this contribution, the author discusses their properties and application in clinical practice.