Researchers in Houston Methodist have come up with a way to potentially help infertile mice get pregnant. They used a special protein found in bacteria that decreased the mice’s cholesterol levels by over 40% after just 3 hours. This finding might be very useful because it could potentially help almost 1/5 of women in the US who have trouble having a baby naturally.
Corina Rosales, a scientist at the Houston Methodist Research Institute, and her team are studying a protein called serum opacity factor. In their experiments, this protein showed it can reduce cholesterol levels by over 40% in only three hours – which is really impressive.
Recently, a group of researchers published the results from their study in the Journal of Lipid Research, which is a publication from the American Society for Biochemistry and Molecular Biology.
A certain protein can help bacteria grow, but it also affects cholesterol-carrying molecules and makes it easier for the liver to get rid of extra cholesterol that is blocking pregnancy. Scientists think this protein could even be used as a replacement for drugs like statins, which are currently the standard treatment for having too much cholesterol in your system.
HDL is called the “good cholesterol” and its job is to take excess cholesterol from your various body tissues and carry it to the liver. This helps keeps your cholesterol levels in check. But, if your HDL doesn’t work correctly, then it can mess up how fat gets processed in your body, which can be harmful just like LDL (otherwise known as the “bad cholesterol”). LDL takes cholesterol from the liver and delivers it to the other parts of your body. When there is too much of this kind of cholesterol, it can clog up arteries, which causes diseases.
Henry J. Pownall from the Houston Methodist Research Institute said that both LDL and HDL (two kinds of cholesterol) have a mixture of something called ‘free cholesterol’ and something else called ‘esterified cholesterol.’ He said that free cholesterol can be bad for us, and having any trouble with HDL will increase our risk in getting diseases.
The researchers experimented with mice that had higher levels of “good” cholesterol than usual. While this was good for studying a heart condition called ‘atherosclerosis’, they noticed that these mice were not able to make babies.
Rosales said that cholesterol is very important for animals to be able to have babies. The ovaries have something called ‘HDL receptors’, which means HDL (High-Density Lipoprotein) has a big role in how well an animal can make babies.
The researchers did an experiment on some mice that couldn’t have babies. As they expected, when they gave the mice medicine to make their cholesterol go down (both LDL and HDL cholesterol decreased), the infertility of the mice was fixed—at least temporarily. This made them look more closely at a special kind of protein called serum opacity factor that just affects HDL cholesterol.
Rosales said that Serum opacity factor is necessary to help bacteria during an infection. It was found that it only works with HDL, not LDL or other fats. So they thought if they could give this same stuff to mice, maybe it would help them become fertile again.
The team did a new experiment where they used a special virus to help mice with high cholesterol levels. The virus gave the mice something called serum opacity factor which lowered their bad cholesterol and made them fertile again.
The scientists just did an experiment that showed good results, so now they want to do another one. They will look at a group of ladies who have infertility issues but don’t know why. If these women have high levels of HDL, the researchers think it could mean future treatments may involve something called serum opacity factor.
Rosales said that even if our research could help only 1% of women trying to have a baby, it would be really helpful and beneficial to them.
An important research article was recently published on 31 December 2022, in the Journal of Lipid Research called “Serum opacity factor rescues fertility among female Scarb1−/− mice by reducing HDL-free cholesterol bioavailability”. The authors, Corina Rosales, Dedipya Yelamanchili, Baiba K. Gillard, Jing Liu, Antonio M. Gotto and Henry J. Pownall studied how a chemical might help to improve fertility for certain types of female mice. They found out that this special molecule could help lower the amount of cholesterol in their bodies which improved fertility levels for these animals.
Four people – Dedipya Yelamanchili, Baiba K. Gillard, Jing Liu and Antonio M. Gotto Jr. – worked together for the study at two different research institutes: the Center for Bioenergetics and Department of Medicine at the Houston Methodist Research Institute, and Weill Cornell Medicine’s Department of Medicine. The National Institutes of Health and the Bass Endowment funded this project.