Berkeley -- When stretched, a type of adult stem cell taken from bone marrow can be nudged towards becoming the type of tissue found in blood vessels, according to a new study by bioengineers at the University of California, Berkeley.

Researchers placed mesenchymal stem cells onto a silicone membrane that was stretched longitudinally once every second. It was a cellular workout routine that helped point the bone marrow stem cell in the direction of becoming the smooth muscle tissue of vascular walls.

The findings, published today (Monday, Oct. 23) in the online early edition of the Proceedings of the National Academy of Sciences, highlight the importance of mechanical forces in stem cell differentiation.

Mesenchymal stem cells have the ability to turn into different types of connective tissue including bone, cartilage and muscle. Embryonic stem cells have the advantage of being able to turn into any kind of body tissue and of being easier to work with in the lab, though that flexibility comes with controversy and ethical questions not found in research on adult stem cells.

But research on both types of stem cells holds the promise of treatment for diseased or damaged body parts. Experiments in stem cell differentiation, however, have traditionally relied upon chemical signals to prompt this transformation into the desired cell type.

Song Li, UC Berkeley associate professor of bioengineering and principal investigator of the study, heads one of the leading research groups in the country investigating the role of a stem cell's physical environment on its development.

"The mechanical effects on the body are well known. A good example is when astronauts in space experience a loss of bone mass because there is no gravity," said Li. "We are now extending this concept to the cellular level by showing that mechanical stimulation can impact stem cell differentiation."

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Contact: Sarah Yang
scyang@berkeley.edu
510-643-7741
University of California - Berkeley
23-Oct-2006