Elusive 'Ambulance' Cells Are Created

May 08, 05:00 AM

Current Headlines: By Dan Vergano

The cells that help build the body's supply of blood and arteries have been created from human embryonic stem cells in substantial numbers for the first time, scientists reported Monday.

The cells have shown promise in lab animal treatment of diabetes, heart disease and wounds.

A team led by Shi-Jiang Lu of Advanced Cell Technology in Worcester, Mass., reports the creation of these precursor cells, called "hemangioblasts," in the journal Nature Methods. "We have been hunting these elusive cells for years," ACT's Robert Lanza says. "We're calling them 'ambulance' cells. They're very smart. We inject them into veins, and they head to repair sites."

Hemangioblasts develop early in embryonic development. Only last month in the journal Blood, Mount Sinai School of Medicine researchers first isolated hemangioblasts grown from early human embryos.

ACT is best known for its announcement in 2001 of an unsuccessful attempt to create a line of stem cells from a cloned human embryo. Embryonic stem cells are precursors to almost every tissue in the body. In the new study, the ACT team reports growing billions of hemangioblasts from eight human embryonic stem cell types. They report using them to treat diabetic rats, as well as damaged blood vessels in mice.

"Overall, I would say that this is a very promising study," says Valerie Kouskoff of the United Kingdom's Paterson Institute for Cancer Research, who was not part of the study. But all transplantations were performed in mice and rats, not people, and were short-term, she cautions.

Lanza agrees but says that if safety studies show progress, his team may seek approval for human testing in 2008. In theory, hemangioblasts could create large numbers of "universal donor" blood cells for transfusions in emergencies, he says. (c) Copyright 2005 USA TODAY, a division of Gannett Co. Inc.