Involvement of Fas/Fas‐L and Bax/Bcl‐2 Systems in Germ Cell Death Following Immunization With Syngeneic Testicular Germ Cells in Mice

Abstract

Experimental autoimmune orchitis (EAO) is characterized by T cell-dependent lymphocytic inflammation and seminiferous tubule damage, which can result in the death of germ cells. The aim of the present study is to investigate the roles of the Fas/ Fas-L and Bax/Bcl-2 systems in the death of germ cells in mice with EAO that is induced by immunization with syngeneic testicular germ cells (TGC). The results using real-time reverse transcriptionpolymerase chain reaction and immunostaining show that many terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining germ cells were present in seminiferous tubules during the active inflammation stage, and these cells were persistently observed in the seminiferous epithelium until the postactive inflammation stage. Intratesticular mRNA expression levels of both Fas and Bax were increased during the active inflammation stage and were dramatically decreased during the post-active inflammation stage. In contrast, the intratesticular mRNA expression levels of both Fas-L and Bcl-2 did not show significant changes during the active inflammation stage but showed extreme increases during the post-active inflammation stage. Immunohistochemically, some Fas-and Bax-positive germ cells were detected during the active inflammation stage, but these were hardly found during the post-active inflammation stage. In contrast, some Fas-L-and Bcl-2-positive germ cells were found during the active inflammation stage, and many of these were also observed during the post-active inflammation stage. These results indicate that germ cell death during TGC-induced EAO is mediated by the Fas/Fas-L and Bax/Bcl-2 systems during the active inflammation stage but not during the post-active inflammation stage.

The Effects of Adjuvants on Autoimmune Responses Against Testicular Antigens in Mice

“…Th1 cells (involved in delayed-type hypersensitivity) produce TNF-α and IFN-γ, whereas Th2-cells (involved in humoral immunity) produce IL-6 and IL-10 [13, 14]. Apoptosis is one of the main features characterizing germ cell death in the testes and is mediated by the Fas/Fas-L systems [15, 16]. Quantitative real-time PCR was performed in duplicate in a TP800 Thermal Cycler Dice Real Time System (TaKaRa), and the comparative C t method (2∆∆C t ) was used to quantify gene expression levels.…”

The Immunophysiology of Male Reproduction

“…291 The pro-inflammatory cytokines, TNF and IFNγ, FAS and FASL, and NOS2 have been identified as potential causative factors in the development of orchitis, principally by stimulating antigen-presentation activity and spermatogenic cell apoptosis. 595,[890][891][892][893][894] Although IL6 production by testicular macrophages increased during experimental autoimmune orchitis in rats, 895 and was implicated in the disruption of the inter-Sertoli cell tight junctions, 896 administration of IL6 has been shown to inhibit the progression of orchitis in LPS-resistant mice. 897 The progression of orchitis may also be inhibited by IL10 and by androgens.…”

Menoprogen, a TCM Herbal Formula for Menopause, Increases Endogenous E2in an Aged Rat Model of Menopause by Reducing Ovarian Granulosa Cell Apoptosis

“…Bcl-2 is an antiapoptotic gene, and its protein is present as a buffy particle with strong expression in normal cells but is present in very low concentrations or absent in the cytoplasm of apoptotic cells [ 21 ]. A significant increase in the positive expression of Bcl-2 proteins (darker color) was observed in the GCs of normal control rats ( Figure 3(a) ), the Menoprogen group ( Figure 3(c) ) and Progynova group ( Figure 3(h) ), compared with the negative expression in NAM group ( Figure 3(b) ).…”

“…Moreover, Bcl-2 expression in the Progynova group was higher than in the Menoprogen group showing that Progynova reduced GC apoptosis better than Menoprogen ( Figure 3(d) ). Bax is a proapoptotic molecule, and Bax proteins are more highly expressed in apoptotic cells than in normal cells [ 21 ]. In this study, the GCs from normal control rats weakly expressed Bax proteins as shown in Figure 3(e) by a lighter color.…”