Nerve growth factor receptor role on rabbit sperm storage

Area of Science:

• Reproductive Biology
• Cell Signaling
• Animal Science

Background:

• Nerve growth factor (NGF) plays a role in male reproduction, with its effects often mediated by tropomyosin receptor kinase A (TrKA) and p75 neurotrophin (p75NTR) receptors on sperm.
• Understanding NGF's role and its receptor dynamics is crucial for optimizing sperm preservation techniques.

Purpose of the Study:

• To investigate the role of NGF and its receptors (TrKA, p75NTR) in rabbit sperm quality during in vitro storage.
• To assess how sperm storage affects NGF receptor abundance and signaling.
• To evaluate the impact of exogenous NGF and receptor neutralization on sperm parameters over time.

Main Methods:

• Rabbit semen samples were stored in vitro for 0-12 hours, with assessments every 4 hours.
• Sperm kinetic parameters, and apoptotic, necrotic, and live sperm percentages were analyzed.
• Experiments involved receptor neutralization (TrKA, p75NTR) and addition of exogenous human NGF.

Main Results:

• NGF receptor abundance changed over storage time, with a significant increase in p75NTR after 8-12 hours.
• Neutralizing TrKA increased sperm speed, capacitation, necrosis, and apoptosis; neutralizing p75NTR improved motility and live cells.
• Exogenous NGF addition at 0 hours improved sperm traits, but effects were null or negative after 4-8 hours of storage.

Conclusions:

• NGF influences rabbit sperm kinetics and physiological traits (capacitation, apoptosis, necrosis) in a time-dependent manner during in vitro storage.
• These NGF effects are modulated by TrKA and p75NTR receptors, whose expression levels change significantly during storage.
• The findings highlight the dynamic interplay between NGF, its receptors, and sperm viability during preservation.