Fas-Fas ligand system as a possible mediator of spermatogenic cell apoptosis in human maturation-arrested testes.
To elucidate the mechanism of maturation arrest, known as one of the male infertility, we addressed whether germ cell apoptosis occurs during maturation arrest, and if so, whether Fas and Fas ligand expressions are involved in the apoptosis. By electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL), typical apoptotic features were frequently found around the spermatocytic stage in maturation arrest, compared to that in normal testes. When paraffin-embedded sections reacted with anti-Fas antiserum, staining for Fas was found in the plasma membranes of spermatocytes in the maturation-arrested testes, while no positive spermatogenic cells were seen in the normal testes. On the other hand, positive immunostaining for Fas ligand was restricted to Sertoli cells in the maturation-arrested testes as well as in the normal testes, although the intensity of staining for Fas ligand in normal testicular Sertoli cells was much weaker than that of maturation-arrested ones. Thus, these findings demonstrate that "maturation arrest" is characterized by frequent apoptosis of spermatocytes, and that Fas and Fas ligand staining are associated with a high frequency of apoptosis.
Department of Urology, Nagasaki University School of Medicine, Japan. eguchi-j@net.nagasaki-u.ac.jp
Jiro
J
Eguchi
Takehiko
T
Koji
Koichiro
K
Nomata
Akira
A
Yoshii
Masashi
M
Shin
Hiroshi
H
Kanetake
D000328:Adult; D017209:Apoptosis; D053222:Fas Ligand Protein; D005854:Germ Cells / Q000166:cytology; D006801:Humans; D020287:In Situ Nick-End Labeling; D007248:Infertility, Male / Q000209:etiology; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism / Q000502:physiology*; D009845:Oligospermia / Q000209:etiology; D013079:Sperm Maturation / Q000502:physiology*; D013091:Spermatogenesis / Q000502:physiology*; D013737:Testis / Q000166:cytology*; D019014:fas Receptor / Q000378:metabolism / Q000502:physiology*
C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins; D019014:fas Receptor