Comparative proteome and lipid profiles of bovine epididymosomes collected in the intraluminal compartment of the caput and cauda epididymidis

Abstract

During the epididymal maturation, spermatozoa interact with different populations of epididymosomes and sequentially acquire some epididymosome-associated proteins critical to sperm functions. Although very few proteins associated with epididymosomes have been identified, the physiological importance of these vesicles in the sperm maturation remains unclear. To document these relevant issues, lipid and protein analysis of epididymosomes from caput and cauda epididymal fluids was determined. Lipid analysis revealed a particular composition of specific phospholipids in these vesicles; the levels of phosphatidyl-ethanolamine, phosphatidyl-inositol and phosphatidyl-choline being higher in caput epididymosomes. From the 555 and 438 proteins identified in caput- and cauda-derived epididymosomes, respectively, 231 proteins were identified in both types of epididymosome. Proteins exclusively identified in caput and cauda epididymosomes are mainly enzymes and transporter molecules. The presence of several glycan-modifying enzymes is the hallmark of the caput epididymosomes proteome. Among the common proteins in both types of epididymosome, a subset of Rab and SNARE proteins implicated in vesicle trafficking and membrane fusion were identified. Together, these data suggest that epididymosome-associated proteins are involved in various molecular functions suggesting that during the epididymal transit, spermatozoa interact with different populations of epididymosomes, which could modify the male gamete in a sequential manner.

Epididymosomes, prostasomes, and liposomes: their roles in mammalian male reproductive physiology

“…In bovine (Girouard et al 2011) as in murine (Rejraji et al 2006) species, the cholesterol: phospholipid ratio of epididymosomes increases by 1.5-fold from caput to cauda segments. In mice, epididymosomes are enriched in sphingomyelin and polyunsaturated membranous fatty acids, especially in arachidonic acids.…”

“…Sphingomyelin concentration in epididymosomes increases during epididymal transit and represents half of the phospholipids in the caudal epididymosomes in murine cauda (Rejraji et al 2006). Phosphatidylinositol, phosphatidylcholine and sphingomyelin also decrease along the epididymis (Girouard et al 2011). Interestingly, cholesterol and sphingomyelin are concentrated in lipid rafts, also named detergentresistant membrane (DRM), at least in cauda epididymosomes in bulls.…”

“…In 2011, Girouard et al (2011) described the proteome of epididymosomes collected in the caput and cauda epididymidis in bovine. Five hundred and fifty five and 438 proteins were identified in caput and cauda epididymosomes respectively, 231 proteins being common to both types of epididymosomes.…”

Prostasomes: extracellular vesicles from the prostate

“…Many of these molecules are transferred by epididymosomes, membrane vesicles that are thought to be shed from the epididymal plasma membrane in an apocrine fashion and can thus be characterised as microvesicles (Cornwall 2009). Epididymosomes have heterogeneous diameters ranging from w0.1 to 1 mm and are produced throughout the epididymal duct, with their precise protein composition depending on the segment of epididymis in which they originate (Girouard et al 2011). Epididymosomes transfer specific subsets of epididymal membrane proteins to the sperm cell surface (Frenette et al 2002;Fig.…”

More Than a Simple Lock and Key Mechanism: Unraveling the Intricacies of Sperm-Zona Pellucida Binding

“…Nevertheless, a number of proteins have been shown to be acquired by the sperm during epididymal transit. A non-exhaustive list of these proteins include HE5/CD52 (Kirchhoff and Hale, 1996), members of the ADAM family (Girouard, et al, 2011, Oh, et al, 2009), SPAM1 (Zhang and Martin-Deleon, 2003) and other hyaluronidases Sullivan, 2001, Legare, et al, 1999), macrophage migration inhibitory factor (MIF) (Eickhoff, et al, 2001, Girouard, et al, 2011 as well as a number of enzymes including aldose reductase and sorbitol dehydrogenase (Frenette, et al, 2004, Frenette, et al, 2006, Kobayashi, et al, 2002, Thimon, et al, 2008. Collectively these proteins are believed to participate in the modification of the sperm biochemistry and surface architecture conferring the potential to engage in oocyte interactions.…”