This story is one in a series marking International Women and Girls in Science Day. Join us as we celebrate some laboratory leaders taking research to new heights.

Pluripotent stem cells are self-renewing and can develop into any cell in the human body. But whether they produce new cells – and if so, how many and what kind – is dictated by factors within the stem cells as well as the environment around them. Molecular signals from surrounding tissues coax stem cells to differentiate into stomach or blood or brain precursor cells, for instance.

In recent years, researchers used this knowledge to develop stem cell therapies that offer hope for treating diseases like Parkinson’s, macular degeneration and osteoarthritis, by replacing damaged or diseased cells with healthy ones. UC San Francisco Anatomy Professor Leanne Jones, PhD, is at the forefront of studying how stem cells are influenced by their surrounding environment and directed to differentiate into one type of cell or another – research that’s critical for stem cell therapies to be successful.

Jones’ work shows that in fruit flies’ testes and intestines, stem cells and the tissues around them – called the stem cell niche – change with age. The findings challenge the idea that youthful stem cells alone can be used to treat age-related or degenerative diseases, at least for older individuals.

“Transplanting stem cells made in a lab into someone with a degenerative disease like Parkinson’s might be a possible treatment,” Jones says. “But what our research demonstrates is that it might not be enough to put a new stem cell into an old person, if the stem cell niche has also aged and can’t support the transplanted cell. That would be a significant problem.”

In 2021, Jones moved her lab to UCSF to launch and direct the new Bakar Aging Research Institute. She couldn’t pass up the chance to bring people from a variety of disciplines together to study aging and develop approaches to treating diseases that are more prevalent in older adults.

Jones hasn’t always been a stem cell biologist, though. In graduate school at Harvard, she studied how human papilloma virus (HPV) triggers out-of-control cell growth, causing cervical cancer. After earning a doctoral degree in microbiology and molecular genetics, she took a position as a postdoctoral fellow in a U.K. lab that probed fruit fly wing development. She discovered that a genetic mutation that disrupted fruit fly wing development also disrupted stem cell behavior in fly ovaries, so that they didn’t correctly produce eggs. Wanting to know more about stem cell biology, Jones moved to Stanford in 2000 to study with Margaret Fuller, a pioneer in the field.

She attributes the jumps in her career to following what interests her. Each step, she believes, helped her grow as a scientist and provided her with new tools.

“Some people think that what makes a truly stellar scientist is someone who can dig down deeper and deeper into one topic until they completely understand it,” says Jones. “But I think it’s important for young scientists to realize that moving into different fields in science can also be valuable. You don’t have to stay tied to one problem and approach for decades. In fact, moving to a new field often means you have a unique perspective, which often gives you a major advantage.”

Julie B. Sneddon stands and smiles against an abstract backdrop of research imagery


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