Body temperature (37 C) specifically down-regulates the messenger ribonucleic acid for the major sperm surface antigen CD52 in epididymal cell culture

Abstract

To study the role of scrotal vs. body temperature in epididymal function we established a simplified cell culture system from the dog epididymis in which the cells showed a pattern of gene expression similar to that in the human epididymis and retained many characteristics of epididymal epithelial cells. The cultured cells had an epithelial type cytoskeleton, nuclear androgen receptor protein, and a striking temperature responsiveness. Exposure of the cells to a culture temperature of 37 C, compared to 33 C, had a fast and irreversibly suppressive effect on the levels of an abundant epididymal messenger RNA (mRNA), CE5, which represents the canine counterpart of the human CD52/HE5 mRNA, encoding a major glycosylphoshatidylinnositol (GPI)-anchored sperm membrane glycopeptide. The temperature effect on the mRNA was a direct and specific one, not mediated by temperature influences on the testis and not affecting other epididymal mRNAs. Exposure of the cells to 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole (25 μg/ml culture medium) and cycloheximide (2 μg/ml) suggested that the steady state levels of CD52/CE5 mRNA may be controlled posttranscriptionally by changing the half-life of this specific mRNA in response to an extracellular temperature stimulus.