In a world first, Israeli scientists have derived male and female stem cells from the same person.
The researchers say they have successfully grown nervous system cells from the stem cells, with genetically identical male and female versions.
They note that the cells of the nervous system are a proof of concept and say they are confident that all human cells can be obtained from the stem cells. The breakthrough was outlined in a peer reviewed research, in which researchers around the world were offered the stem cells to explore their possibilities.
The Israeli scientists, from Hadassah Medical Center in Jerusalem, started with cells donated by a man who has both male and female cells because of a genetic syndrome.
The cells were in an international cell bank, and the technology to derive the stem cells isn’t new, but no one took the initiative until now. “I really don’t know why it hasn’t been done yet, because the benefits to medical science are very great,” Prof. Benjamin Reubinoff told The Times of Israel.
Reubinoff, who along with Dr. Ithai Waldhorn, who led the research, said the stem cells he derived could open a new approach to researching diseases and medical treatments.
It is well known that men and women are often affected differently by medical conditions and treatments. But when researchers try to document the differences to advance science, they often get bogged down.
This is because, when people are recruited for studies, gender is only one factor that defines them. It is often unclear whether people respond differently to a disease or treatment because of their gender, their genes, their health background or a range of other factors.
“For the first time, we now have cells that are absolutely genetically identical, but in both male and female versions,” Reubinoff said. “This means we can compare and contrast how they respond to the medication, or use them to model disease, without the ‘noise’ we’re used to.
“In other words, we will know exactly in what ways the cells behave differently in male and female forms, rather than extracting this information from large studies. In studies, results may be due to gender, but equally to genetic differences between participants.”
Reubinoff said a potentially infinite supply of stem cells could be grown from those in his lab, and used for huge numbers of experiments, in universities, hospitals and pharmaceutical companies.
The research began when Waldhorn found rare cells from a man with Klinefelter syndrome. Normally, females have two X chromosomes, while males have one X and one Y chromosome. Klinefelter syndrome causes males to have two X chromosomes and one Y chromosome.
The man who donated the cells used by Reubinoff and Waldhorn is unusual among Klinefelter patients in that his blood has not only the XXY cells that characterize the syndrome, but also small subpopulations of normal male (XY) and female (XX ) cells. . This allowed Reubinoff and Waldhorn to derive genetically identical stem cells in both male and female forms.
Reubinoff hopes that other researchers will replicate their method using cells from some of the other few Klinefelter patients who have XX and XY cells.
He said it is essential to examine the difference in how men and women respond to diseases and drugs. Women have a higher risk of developing, for example, autoimmune diseases such as multiple sclerosis and rheumatoid arthritis, while men are more likely to experience significant morbidity when infected with COVID-19 and other infectious diseases.
There are also differences in cardiac morbidity and various psychiatric disorders. In addition, there are differences between the sexes in the effectiveness and side effects of medicines.
“This is a breakthrough in gender medicine,” Reubinoff said. “The medical world today recognizes the great importance of the differences between women and men.
“The National Institutes of Health in the US has changed its policy in recent years and now requires all medical research it funds to be conducted equally on both sexes. The unique stem cell system we have developed will lead to new discoveries about sex differences and can help compare drug efficacy and toxicity.”