Extracellular Reactive Oxygen Species (ROS) Production in Fresh Donkey Sperm Exposed to Reductive Stress, Oxidative...

Area of Science:

• Reproductive Biology
• Immunology
• Cellular Physiology

Background:

• Semen influx into the uterus causes a significant endometrial reaction involving polymorphonuclear neutrophils (PMN).
• PMN play a role in sperm selection via phagocytosis and neutrophil extracellular traps (NETs), influencing reproductive outcomes.
• Sperm metabolism and PMN interactions generate reactive oxygen species (ROS), affecting fertility.

Purpose of the Study:

• To investigate extracellular reactive oxygen species (ROS) production in donkey sperm and PMN.
• To determine the role of seminal plasma (SP) and other factors in PMN NETosis and ROS generation.

Main Methods:

• Donkey sperm were subjected to reductive (glutathione - GSH) and oxidative (hydrogen peroxide - H2O2) stress.
• PMN underwent NETosis when exposed to semen, sperm, SP, or formyl-methionyl-leucyl-phenylalanine (FMLP).
• Extracellular H2O2 levels were quantified using the Amplex® Red Hydrogen Peroxide/Peroxidase Assay Kit.

Main Results:

• Donkey sperm exhibited greater resilience to oxidative stress compared to reductive stress.
• GSH treatments resulted in increased extracellular H2O2 production by sperm.
• Seminal plasma was identified as a primary inducer of PMN NETosis and maintained extracellular H2O2 levels.

Conclusions:

• Seminal plasma is crucial in initiating PMN NETosis and modulating ROS production during the uterine response to semen.
• Understanding ROS dynamics in sperm-PMN interactions is vital for assessing reproductive success.