Abstract
One of the most exciting discoveries of recent times is the regenerative capacity of adult stem cells. While hematopoietic stem cells were identified in the 1960s, representing the prototypic “adult stem cell,” the pace of knowledge about endogenous tissue committed stem cells has significantly advanced in the past two decades. Lung stem cells play a pivotal role in homeostasis and regeneration, but poorly functioning endogenous stem cells contribute to aberrant lung repair and remodeling. This biological insight has increased our understanding of the role of stem cells in lung development, and new therapeutic opportunities are emerging. Mesenchymal stromal/stem cells (MSCs) are a heterogeneous population of multipotent stem cells with potent lung regenerative properties. Preclinical studies demonstrate that MSCs reduce neonatal lung injury and pulmonary hypertension. Cell-free approaches such as MSC-derived extracellular vesicles also preserve lung development in experimental bronchopulmonary dysplasia models and are being investigated for a myriad of other neonatal lung diseases. Induced pluripotent stem cells (iPSCs) are being investigated as a platform to recapitulate lung developmental processes, explore novel mechanisms of disease, and test drug efficacy and toxicity.