In Vivo Organ Regeneration via Stroma-Dependent Adult Lineage Reprogramming (mRNA)

Remarkable progress has been made in cell fate reprogramming by forced expression of a small number of transcription factors. Major challenges remain, however, in regenerative medicine regarding how to target multiple cell types and direct them to form a functional organ in vivo. Here, we demonstrate that, by changing their stromal microenvironment, adult differentiated cells of endodermal origin can be reprogrammed to generate a functional ectodermal organ. The process of organ regeneration is highly efficient and complete, and depends on epithelial-stromal interactions that lead to successful remodeling of the extracellular matrix and stromal cells that are essential for organ function. Furthermore, it is a multistep process consisting of changes in cell fate, where dedifferentiation occurs more rapidly than redifferentiation, and subsequent morphogenetic reprogramming. Remarkably, neither direct transdifferentiation nor a complete reversion to the pluripotency state is involved in the reprogramming process; instead it features dynamic activities of essential genes that regulate pluripotency and lineage development. Our data have important implications for stem cell biology, cancer biology, and regenerative medicine. Three replicates of adult and reprogrammed mouse lung and mammary cells were profiled for mRNAs