Vasectomy influences expression of HE1 but not HE2 and HE5 genes in human epididymis

Epididymal roles include protection and transport, maturation, and storage of the sperm cells. It is known that these functions are altered under vasectomy, but the consequences of excurrent duct obstruction on the pattern of gene expression along the human epididymis are poorly documented. In order to understand how excurrent duct occlusion affects different epididymal regions, the expression pattern of genes known to be expressed in specific epididymal segments was investigated along the epididymides of vasectomized men. Selected human epididymal complementary DNAs (cDNAs) identified by differential library screening were studied because of their unique messenger RNA (mRNA) distribution along the different epididymal segments. In situ hybridization as well as immunohistologic studies were undertaken to investigate the effect of vasectomy on a gene expressed all along the epididymis (HE1) or more selectively in the proximal (HE2) or distal (HE5) segment. The HE1 transcript was affected by the obstruction of the epididymis with little or no mRNA detectable along the epididymis. The HE1-related antigen was shown by immunohistochemical methods to be reduced within the epithelium of the epididymis of vasectomized men. By contrast, HE5 mRNA and protein, expressed in epithelial cells of the distal epididymis, were not affected by the obstruction of the vas deferens. Similarly, HE2 transcriptional and translational products normally expressed in the caput epididymidis were not affected by vasectomy. These results show that excurrent duct obstruction differentially affects the expression pattern of some specific transcripts and their encoded proteins, probably impairing their fundamental roles in the physiology of the epididymis.