Boar seminal plasma exosomes maintain sperm function by infiltrating into the sperm membrane

Abstract

Seminal plasma ingredients are important for maintenance of sperm viability. This study focuses on the effect of boar seminal plasma exosomes on sperm function during long-term liquid storage. Boar seminal plasma exosomes had typical nano-structure morphology as measured by scanning electron microscopy (SEM) and molecular markers such as AWN, CD9 and CD63 by western blot analysis. The effect on sperm parameters of adding different ratio of boar seminal plasma exosomes to boar sperm preparations was analyzed. Compared to the diluent without exosomes, the diluent with four times or sixteen times exosomes compared to original semen had higher sperm motility, prolonged effective survival time, improved sperm plasma membrane integrity (p < 0.05), increased total antioxidant capacity (T-AOC) activity and decreased malondialdehyde (MDA) content. The diluent containing four times concentration of exosomes compared to original semen was determined to inhibit premature capacitation, but not to influence capacitation induced in vitro. Inhibition of premature capacitation is likely related to the concentration of exosomes which had been demonstrated to transfer proteins including AWN and PSP-1 into sperm. In addition, using fluorescence microscopy and scanning electron microscopy analysis, it was demonstrated that exosomes in diluent were directly binding to the membrane of sperm head which could improve sperm plasma membrane integrity.

The role of semen and seminal plasma in inducing large-scale genomic changes in the female porcine peri-ovulatory tract

“…Of particular interest was the up-regulation of HSD17B8 in the UTJ, suggesting that the SP may play a role in sperm attachment and release from the oviduct reservoir via estrogen signaling regulation. It is known that exosomes present in SP bind to the sperm head membrane and improve membrane integrity 74 . Also, it has been stated that proteins present in SP are involved in the immune and inflammatory response in the uterus 75 .…”

Evaluation of the cryoprotective effect of seminal plasma on llama ( Lama glama) spermatozoa

“…On the other hand, a llama seminal lectin (SL15) that is likely adsorbed to spermatozoa via SP during ejaculation and is probably involved in sperm reservoir formation (Zampini, Sequeria, Argañaraz, & Apichela, ). In other species, some components of SP have been shown to act as protective agents against premature capacitation, which would seem to indicate the need to add a certain percentage of SP to cryopreservation diluents (Du et al, ; Kershaw‐Young & Maxwell, ). All the above denotes the important role of SP in reproductive physiology.…”

Tetraspanins, More than Markers of Extracellular Vesicles in Reproduction

“…Aalberts et al [ 249 ] found the tetraspanin CD9 in human prostasomes and later CD9, specifically associated with 50–150 nm vesicles [ 250 ]. Du et al [ 251 ] observed a positive effect of CD9- and CD63-positive EVs (exosomes) isolated from boar seminal plasma on several parameters of sperm ‘quality’. Sperm showed prolonged effective motility time, improved plasma membrane integrity and antioxidant capacity, and inhibited premature capacitation.…”