Israeli Scientists Might Have a Way to Cure Male Infertility

From left to right Nicolas Brukman, Clari Valansi, and Prof. Benjamin Podbilewicz (Technion)

Israeli scientists have made yet another breakthrough in treating infertility, this time in men. Researchers from the Technion in Haifa say they have found a way, using sperm from mice, to treat male infertility.

Technion researchers have discovered a new phenomenon where sperm from mice can induce non-reproductive cells from hamsters to fuse and form a syncytia – a cell with multiple nuclei. The scientists conducted a study they say reveals a potential new method to test the capacity of sperm to induce cell fusion, which could be used to diagnose male fertility issues.

The study, published in eLife, finds that the degree of this multinucleation is dependent on the fertilizing potential of the sperm. With further validation, the findings could be used in the development of new diagnostic tools for male infertility.

This news come after just the other day Israeli scientists from Bar-Ilan University said they succeeded in producing “laboratory testicles,” artificial testicles grown in a laboratory.

According to the World Health Organization, infertility is estimated to affect around 15% of the world’s population. Johns Hopkins explains male infertility can have many causes. You may not make enough sperm or healthy sperm. You may have a genetic problem like cystic fibrosis. You may have a blockage in your genital tract.

Male infertility is the inability to conceive a child after at least a year of regular unprotected intercourse. It can be a challenging and emotionally difficult experience for both men and their partners. However, there are many effective treatments available. The best treatment for male infertility will vary depending on the individual’s specific circumstances. I

Possible solutions include assisted reproductive techniques, such as in vitro fertilization (IVF). Previously, the hamster oocyte penetration test was used as a way to quantify the ability of a sperm to fertilize an egg – its fusogenic potential. However, this test is now considered obsolete, so there is no current standardized way to specifically analyze the fusogenic potential of a patient’s sperm.

“In mammals, the fusion of the sperm to the plasma membrane of the egg is mediated by the interaction between two proteins: IZUMO1 on the sperm, and JUNO on the egg, or oocyte,” explains co-author Clari Valansi, a lab manager at the Technion’s Faculty of Biology.

“In our previous work, we showed that mouse sperm can fuse to a type of connective cell called fibroblasts that have been altered to express JUNO,” adds co-author Nicolas Brukman, a postdoctoral researcher at the Faculty of Biology. “In this study, we looked to further investigate the mechanisms of mammalian sperm-oocyte fusion.”

The team started by incubating sperm from adult mice with Baby Hamster Kidney (BHK) cells that had been genetically modified to express JUNO. The team were surprised to discover that the sperm cells induced the BHK cells to fuse together and form one cell with multiple nuclei, or a syncytia. This effect was also observed when using the Human Embryonic Kidney cells.

They determined that this multinucleation was dependent on the presence of JUNO. However, this alone was not sufficient to induce the process. Rather, only cells with sperm fused to them formed syncytia, and the level of multinucleation was found to be dependent on the amount of sperm added to the cells. This suggests that the fusion of sperm with JUNO-expressing BHK cells is needed to induce the subsequent multinucleation of the BHK cells.

But don’t get too excited about a cure for male infertility coming any time soon. The scientists acknowledge that they have a lot more work to do before nearing this goal.

“We have described a new phenomenon in which sperm cells can induce the fusion of cells expressing JUNO in culture, resembling the viral-like fusion of cells upon infection,” concludes co-author Prof. Benjamin Podbilewicz, of the Technion’s Faculty of Biology. “As the extent of multinucleation was correlated with the sperm’s fertilizing potential, SPICER could be a step towards the development of a reliable, fast, and simple method for predicting sperm function during the diagnosis of male infertility. It could also be used to predict the success of assisted reproductive techniques such as IVF, or in the agricultural world to evaluate the fertility of stud animals.”