Umbilical cord yields noncontroversial source - Stem Cells

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 a research team at Kansas State University, Manhattan. Animal and human umbilical cord matrix (UCM) cells exhibit the telltale characteristics of all stem cells, namely, the capacity to salt-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 noninvasive manner from an abundant source of tissue that is typically discarded. "Umbilical cord matrix cells could provide the scientific and medical research community with a noncontroversial and easily attainable source of stem cells for developing treatments for Parkinson's disease, stroke, spinal cord injuries, cancers, and other conditions," suggest Mark Weiss and Deryl Troyer of the College of Veterinary Medicine.

Among the 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 findings--they 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. Progress also has been slowed by having a limited number of existing embryonic stem cell lines available for Federally-funded medical research.

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. It gives the cord resiliency and pliability, and protects its blood vessels 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 possibly may remain in the matrix later in gestation or still be there even after the baby is born. The researchers suggest that Wharton's jelly might be a reservoir of the primitive stem calls that form soon after the egg is fertilized. "Our results indicate that Wharton's jelly calls can be expanded in vitro, maintained in culture, and induced to differentiate into neural cells. We think these ceils can serve many therapeutic and biotechnological roles in the future," explains the College of Veterinary Medicine's Kathy Mitchell.

The next step is to evaluate human UCM cells to see if, in addition to forming nerve tissues, they will differentiate into cardiac muscle and the cells that line the blood vessels.