USC Stem Cell scientist Joanna Smeeton, PhD, knows what arthritis can do to people; she’s witnessed the annual exodus out of her native country of Canada during the winter months. As this year’s Broad Fellow, she is exploring stem cell-based approaches to studying and eventually treating this common cause of cold aversion, disability and pain.

Her Broad Fellowship project leverages an important discovery that she and her colleagues recently published in the journal eLife. They found that certain joints in zebrafish jaws and fins have features similar to the type of mammalian joint susceptible to arthritis.

By damaging a ligament that stabilizes the adult zebrafish jaw, she can reliably induce cartilage damage and arthritis. Just as reliably, the zebrafish can repair the damage. The Keck School of Medicine of USC postdoctoral scholar-research associate aims to understand which progenitor cells are regenerating the ligament and cartilage in the zebrafish jaws, and why similar repair fails to occur in humans.

“In the future, these findings may help in devising strategies to stimulate analogous progenitor cells in patients’ joints towards boosting cartilage and ligament regeneration,” she said.

Smeeton first decided to become a scientist thanks to a very different anatomical structure: the human kidney. As a high school student in the city of St. Catharines near Niagara Falls in Ontario, she developed a fascination with this complex organ. At McGill University in Montreal, she majored in anatomy and cell biology, and observed kidneys and other organs in human cadavers in the anatomy lab. For her doctorate, she learned more about kidney development in the lab of Norman Rosenblum, MD, at Toronto’s Hospital for Sick Children and the University of Toronto.

During her postdoctoral studies, she expanded her focus beyond development, into the realm of regeneration.

“I switched to studying cartilage because joint disease seemed like an area that was understudied in the context of natural regeneration and would be ripe for new treatments,” she said.

With support from a two-year postdoctoral fellowship from the California Institute for Regenerative Medicine (CIRM), she joined the USC Stem Cell laboratory of Gage Crump, PhD, in 2014. Since then, she not only has discovered that zebrafish can develop arthritis, but also lent her talents as a soprano to the USC University Chorus and, with her husband Jeremy, parents twins Edie and Isaac. Theirs is a true Trojan family: Jeremy Morris graduated in 2012 with an MFA from the Peter Stark Producing Program at the USC School of Cinematic Arts.

“The twins have made me even more focused in my lab work,” Smeeton said, “because I know that any second that I’m not home with them, I should be giving my 100 percent and really drilling down on the important questions we want to ask.”

— Cristy Lytal