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At present, mesenchymal cells, known to release a series of factors that stimulate tissue repair, and control inflammation, are most commonly harvested from bone marrow. But the new study, headed by Dr. Armand Keating, now suggests that umbilical cord cells outperform bone marrow cells in improving heart muscle function.

The study, released in Cell Transplantation this month, demonstrates that the cells originating from the tissues surrounding the blood vessels of the human umbilical cord, also known as "Wharton's Jelly," outperformed the current gold standard for stem cell therapies for repairing damage to heart muscles, after an induced heart attack when injected directly into the affected area. Dr. Keating calls the HUCPVC results "statistically and significantly better" than bone marrow cells.

Standard heart function tests measured the effect of the therapy after the cells were injected. The HUCPVC cell therapy was twice as effective at repairing damage to heart tissue than no treatment.

"We are hoping that this translates into fewer people developing complications of heart failure because their muscle function after a heart attack is better," states Keating.

Keating and his team will now complete additional pre-clinical studies, and hope to begin clinical trials of the HUCPVC cells on patients within 12-18 months.

Keating is also interested in conducting further research with the umbilical cord cells to overcome the damaging effects of chemotherapy on heart tissue, an agonizing problem for some patients who may be cured of their cancer only to confront heart failure as a result of treatment.

Apart from heart disease, clinical trials with mesenchymal cells are conducted around the world to investigate the treatment of a variety of diseases, including a serious complication of bone marrow transplantation called graft-versus-host disease, autoimmune disorders, neurological diseases and tissue injury arising from lung and liver disease. Today, more than 250 clinical trials are currently being conducted worldwide using mesenchymal cells

The study, published in the current issue of CELL TRANSPLANTATION, is now freely available on-line at http://www.ingentaconnect.com/content/cog/ct/.

"Embryonic stem cells have pluripotent potential," said study co-author Dr. Tang-Yuan Chu of the Buddhist Tzu Chi General Hospital at Tzu Chi University in Hualien, Taiwan. "The sustained maintenance of hESCs depends on a co-culture with an animal based "feeder" that can create the risk for transmitting nonhuman materials and unknown pathogens. To solve this problem, human tissues have been used as feeders."

The expansion of pluripotent hESCs traditionally requires a feeder culture, meaning that a variety of animal and human tissues have been used in feeder cultures.

The researchers note that while hESCs have been successfully co-cultured using human fetal muscle and skin cells, adult fallopian tube epithelial cells, foreskin cells, and bone marrow stem cells, their study used hUCMScs to create a co-culture. They said that using hUCMSCs as a source feeder has several advantages, including their wide availability, ease of handling and low immunogenicity.

However, according to the researchers, when using various mouse or primate tissues, and even when using human tissues for co-cultures, tumor-like formations called "teratomas" - growths containing tissues belonging to all three germ layers - often form. Although undesirable, teratomas have been used as a marker for the ability of stem cells to be able to develop pluripotency.

This study demonstrated that pluripotency development need not necessarily be teratoma forming.

"We suggest that the feeder we developed from hUCMSCs may support the transition of hESCs that does not grow teratomas because, unlike tissue sources for other feeders, by using hUCMSCs we did not use material comprised of all three germ layers," said the researchers.

"In addition to eliminating teratomas, the proposed system also significantly reduces the workload involved in the preparation of new feeder lines," they concluded.

Source : http://www.phys.org/