Bone Marrow Stem Cells Provide Insulin Source

Morphed cells functioned as pancreas cells producing insulin in response to glucose. While the researchers warn that their findings cannot be applied to treating diabetics now, they say the results potentially offer a means of producing unlimited quantities of functional insulin-producing cells culled from the bone marrow of patients with the illness.

Writing in the Journal of Clinical Investigation, study leader Dr Mehboob Hussain says the research suggests that there is an “additional, easily accessible source of cells that are capable of becoming insulin-producing pancreatic endocrine cells”.

Dr Hussain and his team reached their conclusions after using a molecular biology technique called “CRE-loxP”, which allowed them to identify and isolate bone-marrow-derived cells.

Several research groups have reported that embryonic stem cells and cells found in the pancreas can be converted into insulin-producing cells, but until now no one has specifically explored the bone marrow as a source of beta cells – the cells found in the pancreas that are damaged or destroyed in some forms of diabetes.

Dr Hussain and colleagues used CRE-loxP to create male mice with bone marrow cells that produced an enhanced green fluorescent protein only in the presence of activated insulin genes, typically found in pancreatic beta cells.

The bone marrow was then transplanted from the male mice into female rodents in which bone marrow had been destroyed by radiation.

These cells, the researchers found, functioned as insulin-producing beta cells all containing the Y chromosome, which could only have come from a male donor. In addition, the cells secreted insulin in response to glucose, one of the signatures of pancreatic beta cells.

However, the researchers highlight that only 1.7 to 3 per cent of beta cells in the pancreas of the female mice came from transformed bone marrow stem cells and it remains unknown which subpopulation of stem cells in the bone marrow are the actual source of insulin-producing cells.

“We still need to find out how well these converted cells are functioning compared to indigenous beta cells in the pancreas. A lot more work needs to be done.

“Nevertheless, our study demonstrates the potential for using the bone marrow as a source of insulin-producing cells,” said Dr Hussain. Journal of Clinical Investigation March 2003