Researchers may have successfully retrieved stem cells from the skin cells of infertile men and "coaxed" them into producing the precursors for sperm cells.
The pluripotent stem cells (iPSCs) produced sperm precursors when injected in rodent's testes, a Cell Press news release reported.
"Our results are the first to offer an experimental model to study sperm development," Renee Reijo Pera of the Institute for Stem Cell Biology & Regenerative Medicine and Montana State University, said in the news release.
"Therefore, there is potential for applications to cell-based therapies in the clinic, for example, for the generation of higher quality and numbers of sperm in a dish." "It might even be possible to transplant stem-cell-derived germ cells directly into the testes of men with problems producing sperm," she said.
Infertility affects between 10 and 15 percent of all couples, and genetic sources of this condition are relatively common in men. This is usually a result of loss of genes in the Y chromosome, but researchers are not sure how the phenomenon occurs on the molecular level.
The researchers hope to better-understand the "fundamental decision" during early development that allows for the production of sperm cell precursors that lead to sperm. The team hopes to accomplish this by studying cells that do not inherently possess the genes necessary for sperm production.
The team looked at healthy but infertile men that have deletions in three Y chromosome azoospermia factor (AZF) regions.
"They found that iPSCs derived from AZF-deleted cells were compromised in their ability to form sperm in a dish. But when those cells were transplanted into the seminiferous tubules of mice, they produced germ-cell-like cells (though significantly fewer than iPSCs derived from people without the AZF deletion do)," the news release reported.
The study's findings suggest these developmental defects occur relatively late in the differentiation of sperm cells.
"Our studies suggest that the use of stem cells can serve as a starting material for diagnosing germ cell defects and potentially generating germ cells," Pera said. "This approach has great potential for treatment of individuals who have genetic/idiopathic causes for sperm loss or for cancer survivors who have lost sperm production due to gonadotoxic treatments."
