University of Louisville researchers have coaxed stem cells from adult mice to change into brain, nerve, heart muscle and pancreatic cells – a discovery that could lead to therapies for a host of human diseases and possibly end the national debate over use of embryonic stem cells.
“We have found a counterpart for embryonic stem cells in adult bone marrow. This could negate the ethical concerns,” said Mariusz Ratajczak, leader of the research team and director of the stem cell biology program at U of L’s James Graham Brown Cancer Center.
The next step is to replicate the experiment with similar cells identified in adult humans.
“It’s huge. It’s an amazing discovery,” said Ryan Reca, one of the researchers.
Ratajczak was planning to announce the findings this afternoon at the annual meeting of the American Society of Hematology in Atlanta. His team also plans to present a paper tomorrow showing that these type of cells – called “very small embryonic-like” or VSELs – help repair damaged tissue after a stroke in mice.
Although treatments based on this discovery are most likely many years off, the research holds promise for people with heart disease, stroke, diabetes and Parkinson’s disease. Using a patient’s own VSELs to repair damage to their bodies could eliminate the danger of rejection that exists if cells are taken from a donor.
Dr. Scott Whittemore, scientific director of the university’s Kentucky Spinal Cord Injury Research Center, said more research is needed.
“This is a very important first step,” Whittemore said. “There are some major issues that need to be resolved before you can think about” translating this research into concrete therapies.
Doctors and researchers have been extremely interested in stem cells because they have the potential to develop into many cell types in the body. Embryonic stem cells are able to give rise to any type of cell except those needed to develop a fetus, according to the National Institutes of Health.
Although the potential for adult stem cells has been thought to be more limited, the use of embryonic stem cells has been controversial because it involves the destruction of embryos, which opponents say amounts to the destruction of human life.
“Specifically, embryonic stem cells are derived from embryos that develop from eggs that have been fertilized in vitro – in an in vitro fertilization clinic – and then donated for research purposes with the informed consent of the donors,” according to a stem cell primer from the National Institutes of Health.
In 2001, President Bush restricted federal funding of research to existing lines of cells developed from embryos. He cited ethical concerns – voiced strongly by conservative Christian groups – that destroying such embryos to extract their stem cells destroys human life.
But many researchers and liberal religious groups have persisted in urging such funding, saying embryonic stem cells hold the best potential for medical research. They also say some of the older stem cell lines funded under Bush’s policy have been contaminated and are not as useful as producing new ones would be.
Ratajczak’s recent discoveries are groundbreaking because they show that newly identified adult cells appear to act like embryonic stem cells. He first described a strategy for identifying and isolating them in a 2004 issue of the journal Leukemia. But that earlier research also showed that VSELs are very rare and difficult to grow in a laboratory.
The research announced today appears to show that VSELs can be grown in the laboratory, multiply into clusters of cells and then be caused to change into other types of cells such as brain or cardiac muscle cells.
In their experiment, they extracted bone marrow cells from adult mice, put them into a cell sorter to extract the VSELs, put those cells into a petri dish and used a confidential process that is part of a patent application by U of L. Then, the cells were exposed to chemicals generated by the body called “factors” and changed into cardiac muscle cells, pancreatic cells, nerve cells and brain cells.
“We’ve established how to isolate and how to unleash the power of this cell,” Ratajczak said.
By Laura Ungar – The Courier-Journal
