title: Regulation of activin and inhibin in the adult testis and the evidence for functional roles in spermatogenesis and immunoregulation.
abstract: Activin A provides a unique link between reproduction and immunity, which is especially significant in the adult testis. This cytokine, together with inhibin B and follistatin acting as regulators of activin A activity, is fundamentally involved in the regulation of spermatogenesis and testicular steroidogenesis. However, activin A also has a much broader role in control of inflammation, fibrosis and immunity. In the Sertoli cell, activin A is regulated by signalling pathways that normally regulate stress and inflammation, signalling pathways that intersect with the classical hormonal regulatory pathways mediated by FSH. Modulation of activin A production and activity during spermatogenesis is implicated in the fine control of the cycle of the seminiferous epithelium. The immunoregulatory properties of activin A also suggest that it may be involved in maintaining testicular immune privilege. Consequently, elevated activin A production within the testis during inflammation and infection may contribute to spermatogenic failure, fibrosis and testicular damage.
authors.affiliation: Monash Institute of Medical Research, Monash University, Melbourne, Victoria, Australia. mark.hedger@monash.edu
authors.forename: Mark P
authors.initials: MP
authors.lastname: Hedger
authors.forename: Wendy R
authors.initials: WR
authors.lastname: Winnall
mesh_terms: D028341:Activins / Q000378:metabolism* / Q000502:physiology; D000818:Animals; D006801:Humans; D056747:Immunomodulation; D007249:Inflammation / Q000378:metabolism; D007265:Inhibins / Q000378:metabolism* / Q000502:physiology; D008297:Male; D015398:Signal Transduction; D013091:Spermatogenesis; D013737:Testis / Q000276:immunology / Q000378:metabolism* / Q000473:pathology
chemical_list: D028341:Activins; D007265:Inhibins