Lipidomics of equine amniotic fluid: Identification of amphiphilic (O-acyl)-ω-hydroxy-fatty acids.

This research examines the composition of horse amniotic fluid, focusing on its lipid components. The unique lipid (O-acyl)-ω-hydroxy-fatty acids (OAHFAs) were discovered, suggesting a significant function in specialized compartments like the fetus’s skin or lungs.

Lipidomics Analysis of Equine Amniotic Fluid

• The researchers carried out an extensive non-targeted lipidomic analysis of equine (horse) amniotic fluid using high-resolution mass spectrometry. They wanted to build upon the current limited data for equine amniotic fluid components.
• This investigation revealed a myriad of individual lipids, demonstrating the complex nature of the amniotic fluid. Among these lipids, the researchers made an outstanding discovery: the amniotic fluid contained (O-acyl)-ω-hydroxy-fatty acids (OAHFAs).
• OAHFAs are amphiphilic lipids, which means they possess both hydrophobic and hydrophilic properties. This characteristic may play a crucial role in forming an interface between amniotic lipids and the fetus’s skin or lungs.

Validation of the Lipids and Their Previous Occurrence

• The identities of the OAHFAs were validated through both high-resolution mass spectrometry and tandem mass spectrometry. These methods confirmed the precision of the findings by identifying the fatty acid and hydroxy-fatty acid components within each OAHFA.
• The previous identification of OAHFAs has only been in sperm, meibomian glands, and their secretions. This suggests the unique lipids may contribute significantly to specialized biological compartments. Witnessing these lipids in the amniotic fluid opens up new potential avenues for research into their function.

Potential Roles of the Lipids

• While the researchers identified the presence of OAHFAs in equine amniotic fluid, they were not able to definitively conclude their function in this context. However, they offer some speculation based on the known properties of OAHFAs and their initial findings.
• Given the surfactant properties of OAHFAs and the developmental timeframe during which they were found, the researchers suggest they might serve as lubricants during the delivery process.
• Another proposition is that the lipids are contributing to the development of the fetal lung function as horses are considered precocial species, which are animals that are relatively mature and mobile after birth. The team suggested further investigations to entirely understand the representation and roles of OAHFAs in amniotic fluid.