PHILADELPHIA—Sperm-forming stem cells in the testes can be converted to insulin-producing cells that could replace diseased ones in the pancreas, researchers from Georgetown University Medical Center in Washington, D.C., reported December 12 at the annual meeting of the American Society for Cell Biology. The new technique is edging closer to producing the amount of insulin needed to cure diabetes in humans.
Ian Gallicano, a developmental biologist at Georgetown, and his colleagues isolated sperm-producing stem cells from the testes of organ donors. These cells could easily revert to an embryonic state, capable of making nearly any cell in the body. The Georgetown researchers treated the cells with chemicals to coax them into mimicking beta-islet cells from the pancreas, the same kind of cells that are compromised in diabetes.
Reprogrammed sperm-producing cells cured diabetes in mice for about a week before their insulin levels dropped again. “If you’re a mouse and you have diabetes, you’re in good shape these days,” Gallicano says.
But cells need to make much more insulin in order to cure diabetes in humans. In islet cells in the human pancreas, insulin accounts for about 10 percent of the proteins secreted by the cell. No stem cell from the testes or anywhere else has come close to making that amount of insulin, Gallicano says. He and his colleagues have developed a new way of programming insulin-producing cells and are getting closer to the goal of creating islet-like cells in which insulin accounts for 1 to 10 percent of the proteins in the cells.
Although testes-derived stem cells would be useful only for men, Gallicano thinks the tricks he’s developing could be adapted to other stem cells that could help women with diabetes too.