Rat Sperm 2B1 Glycoprotein (PH20) Contains a C-Terminal Sequence Motif for Attachment of a Glycosyl Phosphatidylinositol Anchor. Effects of Endoproteolytic Cleavage on Hyaluronidase Activity1

Abstract

In the present study we examined the involvement of interleukin (IL)-1α, -1β, FSH, and lipopolysaccharide (LPS) in the regulation of IL-1α and -1β production by Sertoli cells under in vitro conditions. Sertoli cell cultures from immature mice produced constitutively basal levels of intracellular IL-1α. Stimulation of Sertoli cell cultures with LPS (5 μg/ml) resulted in a maximal production of intracellular IL-1α 2 h after the stimulation. Thereafter, these levels decreased but remained significantly higher within 24 h after stimulation than those in control cultures. The effect of LPS on IL-1α production was dose dependent. FSH did not show any effect on intracellular IL-1α production by Sertoli cells. IL-1α could not be detected in supernatants of unstimulated or stimulated Sertoli cell cultures. Sertoli cell cultures stimulated with recombinant IL-1α induced optimal intracellular levels of IL-1α within 2 h of stimulation. These levels remained high 24 h after stimulation. However, stimulation of Sertoli cell cultures with IL-1β induced a peak of IL-1α production 8 h after stimulation. These levels decreased 24 h after the stimulation but were still found to be significantly higher than those in control cultures. The addition of IL-1 receptor antagonist (IL-1ra) to Sertoli cell cultures did not significantly alter their capacity to produce IL-1α. However, the stimulatory effects of recombinant IL-1α on IL-1α production by Sertoli cell cultures were reversed by the concomitant addition of recombinant IL-1ra.