Therapeutic potential of lung epithelial progenitor cells derived from embryonic and induced pluripotent stem cells.

Embryonic stem (ES) cells derived from preimplantation blastocysts and induced pluripotent stem (iPS) cells generated from somatic cell sources are pluripotent and capable of indefinite expansion in vitro. They provide a possible unlimited source of cells that could be differentiated into lung progenitor cells for potential clinical use in pulmonary regenerative medicine. Because of inherent difficulties in deriving endodermal cells from undifferentiated cell cultures, applications using lung epithelial cells derived from ES and iPS cells have lagged behind similar efforts devoted to other tissues, such as the heart and spinal cord. However, during the past several years, significant advances in culture, differentiation, and purification protocols, as well as in bioengineering methodologies, have fueled enthusiasm for the development of stem cell-based lung therapeutics. This article provides an overview of recent research achievements and discusses future technical challenges that must be met before the promise of stem cell applications for lung disease can be realized.