Journal News

Cows offer clues to treat human infertility

Farah Aziz Annesha
April 23, 2024

Infertility is a prevalent problem. Would-be parents struggling to conceive usually try in vitro fertilization, or IVF treatments, in which medical personnel remove an egg from an ovary, fertilize it with sperm in a laboratory and then place the fertilized egg, or blastocyst, in the uterus to grow and develop.

IVF has a low success rate, which physicians and researchers don’t completely understand. In many ways, the lab environment where the egg grows is often not optimal, leading to fewer viable blastocysts that can result in successful pregnancies. Patients often have to repeat the procedure multiple times before they conceive successfully.

Extracellular Vesicles
larryisgood1/NIH Flickr
Extracellular vesicles

The estrous cycle of cows is equivalent to the human menstrual cycle and is similar in structure and function. Cows also experience infertility, with a corresponding lack of knowledge regarding their estrous cycle. However, researchers can study cows more easily than humans, and if they solve infertility in cows, this could serve as a model for treating human infertility.

Researching cow infertility also benefits the dairy industry. Infertile cows are often sent to slaughterhouses, and farmers lose money.

Johanna Piibor, a veterinarian and researcher at the Estonian University of Life Sciences, has had a passion for cattle ever since she began studying veterinary medicine.

“I often observed the lack of diagnostic and prognostic protocols in treating cow infertility,” Piibor said, “and this motivated me to contribute to solving this issue by understanding the science of the estrous cycle.”

To help gain this understanding, Piibor and her colleagues decided to observe the changes in bovine uterine fluid extracellular vesicles, or UF-EVs, at different time points of the estrous cycle.

EVs are heterogeneous particles secreted by cells that carry biomolecules such as proteins, nucleic acids and metabolites and help cells communicate over long distances. The internal content of EVs changes depending on the health of the organism and can influence the response of the cells they deliver their messages to.

UF-EVs contain proteins that are essential in mechanisms of endometrial development. Piibor’s team wanted to see whether these EVs are also important for embryo development.

They took samples of uterine fluid from cows at different phases of the estrous cycle. These cows were synchronized with hormones to induce ovulation at the same time. The researchers isolated EVs from the uterine fluid and observed differences in EV content at each phase. They infused blastocysts in IVF cultures with EVs from different phases of the estrous cycle and observed their effect on the growth of blastocysts.

In a recent article in Molecular & Cellular Proteomics, Piibor and colleagues reported that changes in the UF-EV proteome during the estrous cycle had an impact on blastocyst growth. EVs from the luteal phase of the cycle, when hormones that maintain pregnancy such as progesterone are highly concentrated, significantly increased the rate of blastocyst production. This shows that uterine fluid changes can affect IVF outcomes in cows — and provides clues to increase human IVF success rates.

Piibor’s next step is to compare UF-EVs from cows with clinical endometritis, a uterine inflammation, with those from healthy cows.

Piibor said EV research is a novel field and a challenging aspect is isolating the EVs from the fluid since there is still no agreed-upon isolation method and the technology is not sensitive enough to detect sufficient EVs.

“Optimizing the isolation protocol and developing ultrasensitive technology would allow significant leaps in the field,” she said, “and hopefully will save vast amounts of time in conducting EV research in the future.”

Enjoy reading ASBMB Today?

Become a member to receive the print edition four times a year and the digital edition monthly.

Learn more
Farah Aziz Annesha

Farah Aziz Annesha is an aspiring science writer. She recently graduated from Yonsei University Underwood International College with a B.S. in biotechnology and a B.A. in comparative literature.

Get the latest from ASBMB Today

Enter your email address, and we’ll send you a weekly email with recent articles, interviews and more.

Latest in Science

Science highlights or most popular articles

Computational tool helps scientists create novel bug sprays
Journal News

Computational tool helps scientists create novel bug sprays

May 20, 2025

Rapid discovery of mosquito repellent compounds is enabled through a novel screening platform that combines both computational modeling and functional screening.

Meet Lan Huang
Interview

Meet Lan Huang

May 19, 2025

Molecular & Cellular Proteomics associate editor uses crosslinking mass spec to study protein–protein interactions to find novel therapeutics.

Influenza gets help from gum disease bacteria
Journal News

Influenza gets help from gum disease bacteria

May 15, 2025

Scientists discover that a protease from Porphyromonas gingivalis enhances viral spread. Read more about this recent Journal of Biological Chemistry paper.

How bacteria fight back against promising antimicrobial peptide
Journal News

How bacteria fight back against promising antimicrobial peptide

May 15, 2025

Researchers find a mutation in E. coli that reduces its susceptibility to a potential novel antibiotic. Read more about this recent Journal of Biological Chemistry paper.

New clues reveal how cells respond to stress
Journal News

New clues reveal how cells respond to stress

May 15, 2025

Redox signaling protein may help regulate inflammasome and innate immune activation. Read more about this recent Journal of Biological Chemistry paper.

Innovative platform empowers scientists to transform venoms into therapeutics
Journal News

Innovative platform empowers scientists to transform venoms into therapeutics

May 13, 2025

Scientists combine phage display and a “metavenome” library to discover new drugs that bind clinically relevant human cell receptors. Read about this recent Molecular & Cellular Proteomics paper.