OBJECTIVE: To promote human sperm maturation in vitro. DESIGN: Spermatozoa from the proximal epididymis were coincubated with epididymal epithelial fragments. SETTING: Hospital and research institute. PATIENTS, PARTICIPANTS: Tissue samples were obtained from men undergoing epididymovasostomy procedures or vasectomy. INTERVENTIONS: Fragments of epididymal epithelium formed everted epithelial spheres that in the presence of androgen maintained cell integrity. Coincubation for up to 48 hours of caput epididymal spermatozoa with 3-day-old epithelial cultures from the cauda epididymis was undertaken. MAIN OUTCOME MEASURES: Morphology of epididymal epithelium was assessed by light and electron microscopy. Pulse labeling of tissue in vitro with 35S-methionine was performed with analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis technique and fluorography. Spermatozoa were assessed for progressive motility and their capacity to bind to salt-stored human zona pellucidae. RESULTS: Epididymal fragments formed everted epithelial spheres that maintained cell integrity and functional morphology for 5 to 7 days. Specific proteins were synthesized in culture, in particular, proteins of 20, 22, 40, and 66 kd. Coincubation of caput epididymal spermatozoa with cultures from the cauda epididymis induced a significant increase in progressive sperm motility and sperm binding to salt-stored human zona pellucidae compared with control cultures of epithelium incubated in the absence of androgens or overgrown with fibroblasts. CONCLUSIONS: Aspects of human sperm maturation processes can be mimicked in vitro using coculture techniques with epididymal epithelium. This method may be valuable for improving the fertilizing capacity of human spermatozoa retrieved from the proximal region of the excurrent ducts.
OBJECTIVE: To promote human sperm maturation in vitro. DESIGN: Spermatozoa from the proximal epididymis were coincubated with epididymal epithelial fragments. SETTING: Hospital and research institute. PATIENTS, PARTICIPANTS: Tissue samples were obtained from men undergoing epididymovasostomy procedures or vasectomy. INTERVENTIONS: Fragments of epididymal epithelium formed everted epithelial spheres that in the presence of androgen maintained cell integrity. Coincubation for up to 48 hours of caput epididymal spermatozoa with 3-day-old epithelial cultures from the cauda epididymis was undertaken. MAIN OUTCOME MEASURES: Morphology of epididymal epithelium was assessed by light and electron microscopy. Pulse labeling of tissue in vitro with 35S-methionine was performed with analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis technique and fluorography. Spermatozoa were assessed for progressive motility and their capacity to bind to salt-stored human zona pellucidae. RESULTS: Epididymal fragments formed everted epithelial spheres that maintained cell integrity and functional morphology for 5 to 7 days. Specific proteins were synthesized in culture, in particular, proteins of 20, 22, 40, and 66 kd. Coincubation of caput epididymal spermatozoa with cultures from the cauda epididymis induced a significant increase in progressive sperm motility and sperm binding to salt-stored human zona pellucidae compared with control cultures of epithelium incubated in the absence of androgens or overgrown with fibroblasts. CONCLUSIONS: Aspects of human sperm maturation processes can be mimicked in vitro using coculture techniques with epididymal epithelium. This method may be valuable for improving the fertilizing capacity of human spermatozoa retrieved from the proximal region of the excurrent ducts.
Authors: Bryce D Warren; Soo H Ahn; Kathryn S Brittain; Manjunatha K Nanjappa; Hao Wang; Jianrong Wang; Gustavo Blanco; Gladis Sanchez; Yong Fan; Brian K Petroff; Paul S Cooke; Margaret G Petroff Journal: Am J Pathol Date: 2021-06-11 Impact factor: 5.770