Researchers have discovered new protein biomarkers to visualize well-developed sperm to assess the potential success of surgical sperm retrieval.
In a recent study, researchers have developed a diagnostic test designed to identify functional sperm in infertile men that could revolutionize the approach to male infertility treatment and artificial insemination technology. “Male infertility is a well-known problem that deserves scientific and clinical attention,” said Andrej Drabovich, assistant professor of experimental medicine and pathology at the University of Alberta and corresponding author of the molecular and cellular proteomics study. Drabovic).
One in six couples trying to conceive face infertility problems. In fact, about 10 percent of men in the United States are infertile. The most common cause of severe male infertility is a condition called non-obstructive azoospermia, which causes a lack of sperm in the semen due to poor sperm or sperm development.
Although assisted reproductive technologies have improved exponentially over the past 50 years, extracting sperm from men with NOA can take up to 10 hours in the operating room with varying success rates, Drabovich said.
“Sometimes surgeons can only get a few intact sperm in a procedure that can take hours,” Drabovich said. So he set out to develop a non-invasive way to diagnose NOA and determine whether these men have intact sperm that could fertilize eggs.
“A test that shows the presence or absence of intact sperm in the semen can give a good indication of a patient’s total sperm count,” Drabovich said. “If there are intact sperm cells in the ejaculate, then urologists and surgeons can proceed with the procedure. But finding intact sperm cells among the debris is a huge challenge.”
Drabovich performed mass spectrometry analysis of sperm from men with normal fertility and infertile men with biopsy-proven obstructive azoospermia, or NOA. After analysis, his team identified two proteins, AKAP4 and ASPX, that were present in intact sperm from men with NOA.
Using imaging flow cytometry, they found that ASPX is located at the tip of the sperm, while AKAPA4 is located in the tail. In flow cytometry imaging, the machine takes pictures of individual cells.
After performing these tests, computational algorithms helped researchers image millions of cell debris and undeveloped sperm to identify intact sperm. Because the roles of AKAP4 and ASPX are not fully understood, Drabovich plans to study how they contribute to sperm function.
He also said his work could one day lead to birth control pills for men. “We wanted to see if we could turn it around and try to look at male contraceptives,” Drabovich said. “If we know the function of this protein, we can inhibit it to create a non-hormonal male contraceptive, which is a much-needed medicine.”