Residual bodies and IL-1α stimulate expression of mRNA for IL-1α and IL-1 receptor type I in cultured rat Sertoli cells

The cytokine interleukin (IL)-1 alpha may be produced both by Sertoli cells and immature male germ cells from rat and is thought to play a role in autocrine and/or paracrine regulation of the spermatogenesis. The localization of IL-1 receptors in seminiferous tubules is unknown. In this study we found a constitutive expression of IL-1 receptor type I (IL-1 RI) mRNA in cultured Sertoli cells and peritubular cells from rat, whereas no such transcripts were observed in immature germ cells (pachytene spermatocytcs and round spermatids). An autostimulation of IL-1 alpha mRNA synthesis has previously been described in other cell types. Stimulation of Sertoli cells with recombinant IL-1 alpha for 0-7 h resulted in a rapid increase in both IL-1 alpha and IL-1 RI mRNA. When Sertoli cells were cultured with residual bodies for 0-48 h, mRNA levels for both IL-1 alpha and IL-1 RI were increased in a biphasic manner. We suggest that phagocytosis of residual bodies triggers an autocrine IL-1 alpha loop in Sertoli cells where both IL-1 alpha and one of its receptors are stimulated. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.