Expression of Fas and Fas ligand in normal and ischemia-reperfusion testes: Involvement of the Fas system in the induction of germ cell apoptosis in the damaged mouse testis
T. Koji et al., Expression of Fas and Fas ligand in normal and ischemia-reperfusion testes: Involvement of the Fas system in the induction of germ cell apoptosis in the damaged mouse testis, BIOL REPROD, 64(3), 2001, pp. 946-954
Apoptosis of germ cells is very common in normal and injured mammalian test
es. The aim of this study was to examine the possible involvement of the Fa
s and Fas ligand (FasL) system in the induction of germ cell apoptosis in n
ormal and ischemia-reperfusion testes of adult mice. Apoptosis was assessed
by the TUNEL method and by DNA gel electrophoresis. Fas and FasL mRNAs wer
e detected by Northern blotting and reverse transcription polymerase chain
reaction techniques, and proteins were analyzed by Western blotting and imm
unohistochemistry. Apoptosis of germ cells was identified in the normal tes
tis especially around stages XI and XII, whereas the expression of Fas and
East was largely confined to Leydig cells and Sertoli cells, respectively H
owever, in the testes reperfused after 1 h of ischemia, a high number of TU
NEL-positive cells were identified in parallel with increased Fas-positive
germ cells, whereas FasL expression in Sertoli cells was almost constant ir
respective of the duration of reperfusion. Moreover, i.p. injection of anti
-fas antibody, which blocks the interaction between Fas and FasL, inhibited
apoptosis, as indicated by the reduced number of TUNEL-positive cells, exc
ept for apoptosis at stages XI and XII. Our results indicate that the Fas/F
asL system mediates apoptosis of spermatogenic cells in the injured testis
but not spontaneous apoptosis in the normal testis.