Stem cells from adult human bone helped mice with diabetes make insulin, suggesting new treatments for the disease that afflicts millions of Americans, scientists said Monday.

Injections of the adult stem cells increased insulin levels in about 30 mice with diabetes, a disease that destroys blood sugar control and leaves people vulnerable to lethal complications, said Darwin Prockop, director of the Center for Gene Therapy at Tulane University Health Sciences Center in New Orleans, who co-wrote the study.

About 3 million of the 21 million Americans with diabetes suffer from the Type 1 form that occurs when the body's own immune system attacks insulin-making cells in the pancreas. Injections with bone marrow stem cells may help revive the damaged pancreas, and perhaps help patients avoid kidney, heart and eye disease, Prockop said.

"It's just become apparent over the past year that these bone marrow cells are stemlike and that there are several ways they can repair tissues," he said Monday in a telephone interview. "The results may be dramatic."

The ability of stem cells to mature into many cell types suggests they may be able to treat diabetes, Alzheimer's disease and other conditions resulting from damage to important tissues. Research on adult stem cells has gained importance since 2001 when President George W. Bush restricted government funding for work on human embryonic stem cells.

Embryonic vs. adult

Embryonic stem cells are retrieved from embryos that are several days old. Adult stem cells can come from the tissue of aborted fetuses, umbilical cord blood, or living children and adults. While easier to access, since they can be extracted from living tissue, they are able to take on fewer cell types than embryonic stem cells.

The research, led by Tulane gene therapy researcher Ryang Hwa Lee, will be published this week in the Proceedings of the National Academy of Sciences journal. The study was done with about 30 mice given a chemical that damaged their pancreases, making them diabetic, he said.

After the damage occurred, the mice's pancreases began to fail, so that they almost completely stopped making insulin, and their blood sugar levels began to skyrocket. In people, chronic high blood sugar levels are linked to vision loss, kidney failure, heart attacks and other severe complications that often strike people with diabetes.

Heart to pancreas

Prockop's team injected the adult bone marrow stem cells, which have the ability to mature into several types of cells, into the mice's hearts. Using a genetic marker, he found that the cells had traveled to the pancreas in about two weeks.