"Renovating" Cells

By Jane Farrell

Understanding the molecular signals that guide early cells in the embryo to develop into different types of organs provides insight into how tissues regenerate and repair themselves. By knowing the principles that underlie this transformation, researchers will be able to make new cells at will for transplantation and tissue repair in such situations as liver or heart disease.

Now, investigators at the Perelman School of Medicine at the University of Pennsylvania are able to explain how cell identity changes occur at the very beginning of the process, according to a university news release.

“During my scientific life, I’ve been fascinated by how early cells make ‘decisions’ to turn on one genetic program and exclude others,” said Kenneth S. Zaret, PhD, director of the Institute for Regenerative Medicine and a professor of Cell and Developmental Biology. Zaret and postdoctoral fellow Abdenour Soufi, PhD, led a team that describes this research, which was published in the journal Cell.

What they found could be applied to guiding cells to fates proposed by scientists for a wide variety of biomedical contexts – for example, to better understand molecular changes in the early embryo after fertilization, when one cell type morphs into another. Another application could be to directly change one cell type into another for therapeutic purposes – for example transforming a skin cell directly into a liver, blood, or heart cell.

“We all want to know how to transform one cell into another,” said Zaret. “Now we understand how that happens at the first step. We are working on how the pioneer gene regulatory proteins physically open up the chromatin to loosen it, in preparation for gene activity. These points are fundamentally important for understanding tissue development, cell regeneration, and for making designer cells.”