Studies offer breakthrough for male and female fertility

Couples who are looking to conceive via expensive In vitro fertilisation (IVF) could be given fresh hope for a successful ending after scientists at Cardiff University recently made a breakthrough in their studies into male infertility.

Researchers at the University claim that male infertility could be the result of sperm lacking a particular important protein named PLC-zeta (PLCz), and that eggs that do not fertilise due to male infertility may be treated with this active protein that can ‘kick-start’ its ability to fertilise an egg and increase the chances of a successful pregnancy.

The protein begins a process known as ‘egg activation’, which then starts a chain of biological events required for an embryo to develop.

Lead researcher Professor Tony Lai, commented, “We know that some men are infertile because their sperm fail to activate eggs. Even though their sperm fuses with the egg, nothing happens. These sperm may lack a proper functioning version of PLCz, which is essential to trigger the next stage in becoming pregnant. What’s important from our research is that we have used human sperm PLCz to obtain the positive results that we had previously observed only in experiments with mice. If this protein is inactive or missing from sperm, it fails to trigger the process necessary for egg activation – the next crucial stage of embryo development. However, when an unfertilised egg is injected with human PLCz, it responds exactly as it should do at fertilisation, resulting in successful embryo development to the blastocyst stage, vital to pregnancy success. We’ve established that this one sperm protein, PLCz, is absolutely critical at the point where life begins.”

This news has emerged just days after scientists in Australia published findings that offer hope for women in regards to preserving fertility after undergoing cancer treatment.

Experts at The Royal Melbourne and Royal Women’s Hospitals claim that egg cells, or ‘oocytes’, are not killed off by radiation. They say the damage is done after the result of two proteins – PUMA and NOXA – kick-starting into action after they sense DNA disturbance to egg cells.

The scientists carried out tests on mice that did not have either of these particular proteins and it was discovered that the eggs in the mice managed to survive through radiation therapy, and later went on to have perfectly normal offspring. In fact approximately between 50% to 80% of the eggs managed to survive in the mice.

The discovery means that women receiving cancer treatment could now benefit, as well as women who suffer from premature menopause, of which there is an increased chance of infertility, heart disease and osteoporosis.

Lead author Clare Scott spoke on their findings, saying, “What we found was that if you have an egg cell that doesn’t have this PUMA protein, it can actually survive DNA damage by repairing its DNA. This had not been known before. We didn’t know if these very specialised egg cells were capable of repairing DNA and going on to produce normal offspring. In the mice that we worked with, we found that if PUMA was missing, then normal offspring could result. That has great excitement for our understanding of how to come up with a new treatment to prevent infertility.”

Clare’s team are now using human egg cells in experiments to sustain if the proteins act in the same way. If a similar pattern is noted, they hope to create a drug that will work at preventing the two proteins from interfering with and killing the egg cells and thus allowing women to undergo radiation therapy, protecting their fertility.