The puzzle of how lungs grow has been solved. Scientists watching the process in mice embryos have found that budding and branching of new air sacs is driven by the mechanical stretching of individual cells.
What’s more, they demonstrated that this growth can be adjusted by manipulating mechanical forces involved in the cells’ skeleton, a framework of fine tubes and filaments that give the cell its shape and let it move.

By increasing tension in this so-called cytoskeleton, “We’ve shown that we can speed up lung development, and that we can slow it down by decreasing tension,” says Donald Ingber, Judah Folkman Professor of Vascular Biology at Harvard Medical School. Such a capability might be a first step in finding new ways to prevent, minimize, or even correct human diseases and malfunctions of the lungs. For example, it might produce novel treatments to accelerate lung development in premature infants, who often suffer from incomplete lung development.

“Ingber’s findings could lead to new approaches to treating bronchopulmonary dysplasia, a serious lung disease that affects 30 to 40 percent of all premature babies,” notes Stella Kourembanas, chief of newborn medicine at Children’s Hospital Boston, where the research was done. The new understanding could also be helpful in treating “lung hypoplasia, in which lungs are compressed and cannot develop fully,” she adds.

Ingber and his colleagues reported the details of their research in the February issue of the journal Developmental Dynamics.