A Rich New Stem Cell Source: Research on Umbilical Cord Matrix
Stem cell research. Just the mention of the controversial study stirs up a storm of debate.
The divisive research has become a political hot potato, even emerging as a campaign issue. One presidential candidate has declared it an ethical and moral issue that must not be treated lightly; the other has pledged to lift a partial ban on the research. In California, voters will vote on a measure that would devote $3 billion to human embryonic stem cell experiments.
Even a prominent political family has been split down the middle with regard to the importance of embryonic stem cell research, because it is believed by many that a fertilized embryo constitutes a human being.
A Kansas State University professor of anatomy and physiology has spent his life as a researcher and scientist focusing on genetic neurologic conditions, gene mapping and the use of chromosomal microdissection to generate DNA markers. Recently, the emphasis of Deryl Troyer’s laboratory has shifted to stem cell biotechnology.
Troyer is particularly interested in developing stem cells as a source of replacement cells for somatic cells damaged or lost due to degenerative disease, trauma or aging and their use in targeted delivery of therapeutic peptides or proteins. He has discovered, along with colleagues Mark Weiss, professor of anatomy and physiology in K-State’s College of Veterinary Medicine and Duane Davis, a professor of animal sciences and industry, a novel and potentially inexhaustible source of stem cells isolated from the matrix of umbilical cords.
These cells have a remarkable propensity to develop into neural stem cells. He is presently collaborating in studies to further characterize these cells and develop them for stem cell therapies in animals and humans. Recent work indicated that these stem cells can be xenotransplanted into the brain without being rejected and that they differentiated into neurons.
The cushioning material or matrix within the umbilical cord known as Wharton’s jelly is a rich and readily available source of primitive stem cells, according to findings by Troyer and Weiss. Animal and human umbilical cord matrix cells exhibit the tell-tale characteristics of all stem cells, the capacity to self-renew and to differentiate into multiple cell types.
The cells -- called cord matrix stem cells to distinguish them from cord blood cells -- can be obtained in a non-invasive manner from an abundant source of tissue that is typically discarded. "Unfortunately, people hear the term stem cells and they automatically conclude that it is coming from an embryonic source," Weiss said. "That is an unfortunate connotation that is not always accurate."
According to Weiss and Troyer, "Umbilical cord matrix cells could provide the scientific and medical research community with a non-controversial and easily attainable source of stem cells for developing treatments for Parkinson’s disease, stroke, spinal cord injuries, cancers and other conditions."
The discovery of the matrix stem cells may also lead to important new technologies in animal agriculture and for the preservation of endangered species. Among the group’s findings: Wharton’s jelly cells from pigs were propagated in the lab for more than a year without losing potency; they can be stored cryogenically and engineered to express foreign proteins.
The cells exhibit telomerase activity, a key indicator of stem cells, and they can be induced to form nerve cells, both neurons and glia, that produce a range of nerve-cell specific traits. Neurons are the nervous system cells that transmit signals; glial cells support the neurons. On the basis of the encouraging results with animal tissue, the team broadened its investigations to human umbilical cord matrix cells with similar exciting findings -- human umbilical cord matrix cells differentiate into neurons, too.
Most of the promise of developing embryonic stem cell-based therapies for treating several degenerative diseases of the nervous system as well as other types of disease is hindered by the controversial nature of the cell sources. Research progress has also been slowed by having a limited number of existing embryonic stem cell lines available for federally-funded medical research. "Identifying a non-controversial source of primitive stem cells is a step in the right direction," Davis said.
Wharton’s jelly, discovered in the mid-1600s by Thomas Wharton, a London physician, is the gelatinous connective tissue only found in the umbilical cord. The jelly gives the cord resiliency and pliability, and protects the blood vessels in the umbilical cord from compression.
As an embryo forms, some very primitive cells migrate between the region where the umbilical cord forms and the embryo. Some primitive cells just might remain in the matrix later in gestation or still be there even after the baby is born. The K-State research team suggests that Wharton’s jelly might be a reservoir of the primitive stem cells that form soon after the egg is fertilized. "Our results indicate that Wharton’s jelly cells can be expanded in vitro, maintained in culture and induced to differentiate into cells that express several proteins found in neural cells, and thus may be beneficial in diseases where neurons die," Troyer said. We think these cells can serve many therapeutic and biotechnological roles in the future."
The team now is evaluating human umbilical cord matrix cells to see if in addition to forming nerve tissues the cells also will differentiate into cardiac muscle and the cells that line the blood vessels. They note that important progress is being made in the Weiss and Troyer labs where the researchers are looking at the ability of the umbilical cord matrix cells to form new neurons in the brain, which would aid against Parkinson’s disease.
The KSU Research Foundation has filed for U.S. patent protection for the recent discoveries, the method of culturing the stem cells, and a kit for salvaging umbilical cord stem cells after birth. Funding for this research has come from the National Institutes of Health, a Centers of Biomedical Research Excellence/COBRE award to the University of Kansas, with matching support from the state of Kansas, Kansas State University, University of Kansas, the Terry C. Johnson Cancer Center, the K-State College of Veterinary Medicine and the Kansas Agricultural Experiment Station.
For patent and commercialization information, contact the National Institute for Strategic Technology Acquisition and Commercialization, 785-532-3900. For more about stem cells, see the National Institutes of Health primer at http://www.nih.gov/news/stemcell/primer.htm