A new finding that bone marrow-derived cells give rise to fully functional liver cells suggests that these cells eventually could be used to repair or replace injured or diseased livers, reducing the need for transplantation.
A team at the University of Pittsburgh led by Bryon Peterson, PhD, reported on May 14 in Science that the bone marrow-derived stem cells provide a lineage for cells making up solid organs (1999;284:1168-1170). The finding even gives hope that organs may someday be grown without using human embryonic stem cells—cells that have been the subject of controversy since they were isolated last year, because they must be derived from human embryos.
"At a theoretical level, the findings disrupt the scientific dogma that plastic fetal cells are needed to generate the differentiated cells of adult organs," the University of Pittsburgh Medical Center said in a statement.
In experiments in which the investigators depleted the bone marrow of female rats and replaced it with bone marrow from male rats, bone marrow-derived cells eventually became fully functional liver cells, probably through an intermediate oval cell. "The next step is finding the bone marrow stem cell giving rise to the oval cell or discovering the signal that the liver broadcasts to recruit such cells to the scene of injury." Dr. Peterson said.
Although previous scientific reports have indicated that bone marrow cells give rise to mesenchymal cells and endothelial cells, this report is the first to indicate that bone marrow cells give rise to epithelial cells, which can develop into solid organs.
For Your Information:
University of Pittsburgh Medical Center press release
www.upmc.edu/NewsBureau/stemcells.htm
Please be aware that medical advice, diagnoses and physician references cannot be obtained from this site.