ADRCs (adipose-derived stem and regenerative cells) are a heterogeneous, or mixed population of cells found within adipose (fat) tissue. In addition to adult stem cells, the cell population is rich in other cell types that have potentially useful properties, including endothelial progenitor cells, tissue resident macrophages, microvascular cells, and smooth muscle cells.
There are numerous mechanisms of action by which ADRCs have been shown to have significant impact on certain diseases or medical conditions. Preclinical studies have shown that ADRCs improve blood flow by accelerating the rate of growth of new blood vessels,1 can modulate the inflammatory response through secretion of various cytokines and chemokines,2 and can reduce cell death, thereby creating a microenvironment favoring healing over scarring.3 In addition, ADRCs have shown some capacity to be capable of differentiating into mature cell phenotypes, enabling the replacement of tissue or structures.4
Adipose tissue, a liposuction by-product that is generally considered to be medical waste, is the richest known source of adult stem and regenerative cells in the body. ADRCs help facilitate the natural life cycle of fat tissue by generating new adipocytes (fat cells) to replace the 8-9% of fat cells that get turned over each year. During weight gain, adipose (fat) tissue gets larger as adipocytes fill with lipid and increase in size. As the tissue expands the blood vessels feeding the tissue must also grow. ADRCs assist in this process as well as in the remodeling of blood vessels as they shrink during weight loss.
Preclinical research includes includes spinal cord injury, renal injury, and pulmonary disease, among others. Clinical research with ADRCs is currently underway for breast reconstruction, heart disease, Type 1 diabetes, urinary incontinence, and liver insufficiency, among others.
1. Rehman, J., et al. Secretion of angiogenic and antiapoptotic factors by human adipose stromal cells. Circulation, 2004. 109(10): p. 1292-8.
2. Katz, A.J., et al. Cell surface and transcriptional characterization of human adipose-derived adherent stromal (hADAS) cells. Stem Cells, 2005. 23(3): p. 412-23.
3. Puissant, B., et al. Immunomodulatory effect of human adipose tissue-derived adult stem cells: comparison with bone marrow mesenchymal stem cells. Br J Haematol, 2005. 129(1): p. 118-29.
4. Planat-Benard, V., et al. Plasticity of human adipose lineage cells toward endothelial cells: physiological and therapeutic perspectives. Circulation, 2004. 109(5): p. 656-63.