Adipose-derived stem cells and their potential to differentiate into the epithelial lineage.

Adipose-derived stem cells (ASCs) possess a multilineage differentiation potential, can be used from an autologous origin, and are, therefore, attractive candidates for clinical applications to repair or regenerate damaged tissues and organs. Adipose tissue as a stem cell source is ubiquitously available and has several advantages compared with other sources. It is easily accessible in large quantities with a minimal invasive harvesting procedure, and the isolation of ASCs yields a high amount of stem cells, which is essential for stem cell-based therapies and tissue engineering. Differentiation of ASCs into cell types of mesodermal origin has been shown in a variety of studies. The plasticity of ASCs toward cells of the mesodermal lineage has been shown by their differentiation into chondrocytes, osteoblasts, adipocytes, and myocytes. Their potential to differentiate into lineages with nonmesodermal origin is even more exciting: ASCs are also able to differentiate into cells of ecto- and endodermal origin. Various in vitro and in vivo studies documented the induced differentiation into neural cells, hepatocytes, pancreatic islet cells, endothelial cells, and epithelial cells. Epithelial cells can embryologically arise from each of the 3 germ layers. This article summarizes and discusses the current knowledge of the potential of ASCs to differentiate into the epithelial lineage. The differentiation of ASCs into different types of epithelial cells, including hepatocytes, pancreatic cells, and endothelial cells, is highlighted together with a view on current clinical trials and future options.