The Loh Laboratory employs stem cells to reconstitute and understand human developmental biology. By applying their knowledge of development, they intend to generate pure populations of desired human tissue progenitors and create a platform for stem cell-driven regenerative medicine.

Embryonic stem cells can produce any type of human cell in a dish. Thus they afford an opportunity to recreate, and thus study, basic developmental phenomena (lineage diversification, tissue self-organization and multilineage competence) that are difficult to probe in a developing embryo. However, this opportunity has yet to be fully realized because stem-cell differentiation often yields heterogeneous mixtures of cells that are ill-suited for molecular analysis or cell therapy.

The Loh lab has developed a reductionist system to define the minimal essential inductive and repressive signals necessary for the developmental induction of a given embryonic lineage from differentiating ESCs. These efforts culminated in systematic roadmaps describing the extrinsic signals that guide human ESCs into a variety of endoderm and mesoderm germ layer derivatives (including liver, intestinal, bone and heart progenitors) through a series of bifurcating intermediate steps. The overarching goal is to exploit the resultant highly-pure populations of human tissue progenitors to explore classic questions in developmental biology, using stem-cell differentiation as a technological platform.