Fantastic Four

Meri Firpo traces her quest to find a cure for diabetes all the way back to a grade school biology class, where she was amazed to learn that people start out as a single cell. “I wondered how the cells could divide and make more of the same cells, but then somehow start to change into different kinds of cells, like skin cells and muscle cells,” she recalls.

Firpo is still working on the same question—how stem cells differentiate. But now, as a researcher, she wants to discover how to control that process and produce specific cells needed to treat disease.

“Stem cells are very important for regenerating tissues throughout our life,” Firpo says. The cells exist in all parts of our bodies, even as adults, but they tend to be “pre-specialized” to become more of the organ or tissue from which they derive. With adult stem cells, “we haven’t been very effective at getting those cells to expand outside of the body without specifying,” Firpo says. So she works with embryonic stem cells derived from blastocytes (embryos just a few days old) that are donated for research by patients of in-vitro fertilization clinics.

These cells “come from a stage of the embryo before any tissue specification has occurred,” she explains, and they have unique attributes. “One, they can differentiate into any cell type, which we call ‘pluripotency.’ Two, they are capable of self-renewal, which is the capacity to grow and expand into many, many cells without specifying into any cell type.”

For Firpo, understanding why and how these cells eventually do specify is an essential first step in learning to control their development. Those are the two aims of her lab at the U of M. “Being able to watch these cells in the laboratory specify into different tissues gives us essentially a model of human development,” she explains. “We could then manipulate the cells genetically or manipulate the environment to help us understand where those processes go wrong and lead to disease.”

What’s more, “if we can culture these cells indefinitely so that they remain embryonic stem cells with the capacity to make any cell type in the body, we could then make enough tissues from them to transplant into patients whose cells had been damaged.”