Involvement of mu-calpain in human sperm capacitation for fertilization

Citation
T. Aoyama et al., Involvement of mu-calpain in human sperm capacitation for fertilization, AM J REPROD, 45(1), 2001, pp. 12-20
Citations number
45
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Immunology
Journal title
AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY
ISSN journal
1046-7408 → ACNP
Volume
45
Issue
1
Year of publication
2001
Pages
12 - 20
Database
ISI
SICI code
1046-7408(200101)45:1<12:IOMIHS>2.0.ZU;2-6
Abstract
PROBLEM: The distribution and physiological role of calpains in human sperm were investigated. METHOD OF STUDY: Semen collected manually from healthy donors was liquefied then centrifuged by percoll gradient centrifugation. After exposure to dif ferent concentrations of Ca2+ ionophore A(23187), the samples were used for immunostaining sodium dodecyl sulfate polyacrylamide gel electrophoresis, and western blot analysis. It was speculated from the results of the study using calpain-specific inhibitors that calpain contributes to the sperm mot ility and acrosome reaction. RESULTS: With the anti-pro mu -calpain antibody, sperm were immunostained, whereas all were negative for anti-pro m-calpain antibody binding. Stained sperm were classified into four types according to the staining pattern: ac rosome type, equatorial segment type, whole head type, and neck and tail se gments type. Western blot analysis of sperm homogenate revealed a single 80 -kDa band using the anti-pro mu -calpain antibody, its dose-dependent reduc tion with Ca2+ ionophore A(23187) suggesting activation by this treatment. In the presence of membrane permeable calpain inhibitors, sperm motility an d acrosome reaction were significantly suppressed. CONCLUSION: These results indicate that mu -calpain may play pivotal roles in the process of fertilization of human sperm.