Reporting in the advance online publications section of the science journal Nature, a team of US researchers, led by Catherine Verfaille of the University of Minnesota, has shown that a type of adult stem cell derived from bone marrow (mesenchymal cells) has many of the same characteristics as embryonic stem cells (ES cells).
The researchers took mesenchymal cells from the bone marrow of adult mice and 'genetically marked them to pick up a blue fluorescent dye'. In the initial part of the study, between one and 12 of the cells were injected into early mouse embryos, which were then transferred to surrogate mothers.
Thirty-seven mice were born and allowed to mature, before being killed and autopsied. This showed that some of the internal tissues were dyed. The mice were found to be chimeras - having both their own genetic material and that of the mice that supplied the mesenchymal cells. Some of the mice only had a 'tiny percentage' of tissue developed from the mesenchymal cells, while some had as much as 45 per cent. Verfaille said that although this part of the experiment had little implication in terms of medical treatment in the future, it does demonstrate the versatility of the cells.
In the second part of the study, genetically marked mesenchymal cells were injected into adult mice. After four to 24 weeks, the researchers found that 'colonies' of the new cells had begun to grow in the mice, particularly in the intestines, lungs and liver.
The research has been welcomed by opponents of the use of ES cells and therapeutic cloning. However, Verfaille said that stem cell research with both adult stem cells and ES cells should continue 'in parallel', because 'there may be particular diseases that may be more easily treated with one cell type versus another'.
Sources and References
Study supports versatility of adult stem cells
Study finds potential in adult cells
Pluripotency of mesenchymal stem cells derived from adult marrow