Jurassic Spark - Dino movie inspires stem cell fertility treatment

A new study has shown that certain human bone marrow stem cells can differentiate into sperm stem cells - potentially leading to a revolution in fertility therapy.

The researchers, led by Professor Karim Nayernia of Newcastle University in the UK, managed to encourage mesenchymal stem cells (MSCs) to differentiate into reproductive cells, known as germ cells. 

These cells may provide a new source of male and female germ cells that could, in the future, be used to produce sperm and eggs for patients suffering from infertility. 

But the researchers have cautioned that encouraging these cells to fully mature represents a serious challenge. 

"In the long term the aim would be to isolate these stem cells from a patient and then bring them back to the same patient after differentiation to try to treat infertility," said Nayernia. 

He explained that many types of chemotherapy destroy germ cells and that this research could potentially restore patients' fertility by replacing germ cells in the testes. 

The researchers used immunohistochemical analysis to show that the cells exhibited several markers that are only expressed in male germ cells: Stra8, Piwil2, Dazl and Tspy

The research, published in the latest edition of the journal Reproduction: Gamete Biology built upon previous research by the group that showed that mouse bone marrow could be used to create spermatagonial cells. While these cells were observed to undergo cell division, the next stage in the formation of sperm cells, they did not develop any further. 

The group has also had previous success in converting mouse embryonic stem cells into sperm cells that were successfully used to fertilise mouse eggs that resulted in seven live births. 

"Our next goal is to see if we can get the spermatagonial stem cells to progress to mature sperm in the laboratory and this should take around three to five years of experiments," he said. 

Nayernia explained that using embryonic stem cells to create a cure for infertility would be impossible as there would be no way of obtaining embryonic stem cells from infertile subjects. 

"At the moment we have sperm stem cells and we have some evidence that they can differentiate all the way into sperm cells," said Nayernia. 

MSCs are found in bone marrow along with haematopoietic stem cells, endothelial stem cells and multipotential adult progenitor stem cells. 

Nayernia explained that the isolation of bone marrow stem cells and the separation of MSCs from the other types of stem cell present was now a routine technique. 

After isolating the cells the researchers cultured them in a medium very similar to that found in the testes which encouraged them to differentiate into the germ cells. 

He also spoke of recent work from an American group that managed to use bone marrow stem cells to create cells that support the germ cells, sertoli cells which 'nurse' developing sperm and Leydig cells that secrete various hormones. 

This approach could lead to a fertility cure for men who have healthy germ cells but cannot produce sperm cells as they lack these supporting cells. 

By combining the two approaches Nayernia believes that it may one-day may be possible to take bone marrow cells from extinct species such as the frozen woolly mammoth and recreate the extinct species, much like in the movie Jurassic Park.