HE1/NPC2 status in human reproductive tract and ejaculated spermatozoa: consequence of vasectomy.
We have previously demonstrated that the amount of HE1/NPC2 mRNA and protein expressed in the human epididymis is decreased under vasectomy. In this study, western blot analyses showed that many vasovasostomized men are characterized by high HE1/NPC2 levels in spermatozoa when compared with fertile donors. HE1/NPC2 association with sperm from vasovasostomized men was not related to low motility per se as spermatozoa from asthenospermic men have HE1/NPC2 levels similar to those in normal fertile semen samples. Spermatozoa from vasovasostomized men with high amount of HE1/NPC2 are characterized by higher concentration of cholesterol and more lipid raft domains. HE1/NPC2 is secreted in different glycoforms by different tissues of human male reproductive tract. These forms are due to variation in N-glycosylation, and only the deglycosylated form is associated with spermatozoa from some vasovasostomized men. Compared with normal men, seminal plasma of vasectomized men is characterized by a major decrease in immunodetectable HE1/NPC2 without change in the glycosylation pattern. Following surgical vasectomy reversal, seminal plasma HE1/NPC2 was found in similar amounts to the ones characterizing normal men. Considering the potential role of HE1/NPC2 in cholesterol transport during sperm maturation, unusual high levels of this protein associated with spermatozoa of vasovasostomized men may reflect epididymal sequelae occurring when the vas deferens is obstructed.
Légaré
Christine
C
Centre de Recherche en Biologie de la Reproduction and Département d'Obstétrique-Gynécologie, Faculté de Médecine, Université Laval, 2705 Boulevard Laurier, Ste-Foy, Québec, Canada.
Thabet
Michel
M
Gatti
Jean-Luc
JL
Sullivan
Robert
R
D015153:Blotting, Western / Q000379:methods; D002352:Carrier Proteins / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism; D003720:Densitometry; D004543:Ejaculatory Ducts / Q000378:metabolism; D004822:Epididymis / Q000378:metabolism*; D005298:Fertility; D005677:G(M1) Ganglioside / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012661:Semen / Q000378:metabolism; D013094:Spermatozoa / Q000378:metabolism*; D014659:Vasectomy; D033921:Vesicular Transport Proteins
D002352:Carrier Proteins; D006023:Glycoproteins; C104585:NPC2 protein, human; D033921:Vesicular Transport Proteins; D005677:G(M1) Ganglioside; D002784:Cholesterol