ABSTRACT
I. Introduction Stem cell research has received increasing attention over the past decade with much of the focus centered on the potential tissue regenerative properties these cells possess. While most of the scientific and public attention has focused on the promise of embryonic stem cells (ESCs), given their totipotent potential, there has been a growing movement to investigate the therapeutic potential of adult stem cells. Adult stem cells are tissue specific cells present in organs that have retained the ability to differentiate into a variety of cell lineages thereby making them multipotent. Although adult stem cells do not possess the full range of plasticity that ESCs do, they offer practical advantages such as ease of isolation and propagation, and they are not associated with the political controversy that surrounds ESCs research. One class of adult stem cells that has been of particular interest is mesenchymal stem cells (MSCs). MSCs, also called marrow stromal stem cells, were first discovered in 1968 by Friedenstein (1) who discovered bone marrow stromal cells that were plastic adherent, clonogenic, and fibroblastic in appearance. Since the initial discovery 40 years ago, MSCs have been identified as a unique class of adult stem cells that possess several immune properties that make them a viable candidate for cell-based therapy for a variety of disease processes. This chapter will focus on first describing the basic biology of MSCs, the rationale for using these cells in acute respiratory distress syndrome (ARDS), and then the existing experimental literature that has tested the use of MSCs in models of acute lung injury (ALI) and ARDS. We will conclude with a review of recent attempts to translate the experimental findings with MSCs to patients with ARDS, as well as with a discussion of needed future research directions.
