Potential roles of EPPIN (Epididymal Protease Inhibitor) on post-testicular maturation of mouse spermatozoa: consequences for sperm function

• Grant number: 19/13661-1
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): November 01, 2019
• Effective date (End): April 30, 2021
• Field of knowledge: Biological Sciences - Pharmacology - Biochemical and Molecular Pharmacology
• Principal Investigator: Erick José Ramo da Silva
• Grantee: Alan Andrew dos Santos Silva
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Associated research grant: 15/08227-0 - A study on EPPIN as a drug target for male contraception: developing a new animal model to test the efficacy of male contraceptive drugs, AP.JP

Abstract

EPPIN (Epididymal protease inhibitor) is a member of the WFDC (Whey acidic protein-type four-disulfide core) gene family abundantly expressed in the testis and epididymis. EPPIN is found on the surface of spermatozoa, where it plays a role on sperm motility after ejaculation. It has been demonstrated that blocking EPPIN on the surface of human ejaculate spermatozoa with anti-EPPIN antibodies and small organic compounds targeting EPPIN resulted in the inhibition of sperm progressive motility. These data provided the proof-of-principle that EPPIN can be explored as a drug target for male contraception. Little is known, however, on the roles of EPPIN on post-testicular sperm maturation events, such as epididymal sperm maturation and capacitation, which are crucial to the acquisition of motility and fertilizing capacity of spermatozoa. In this project, we propose to investigate the impact of post-testicular sperm maturation on the expression of EPPIN on mouse spermatozoa, as well as if EPPIN is involved in events associated with sperm motility and capacitation. We will perform Western blot and immunofluorescence assays using spermatozoa isolated from different regions of the epididymis and incubated under non-capacitating and capacitating conditions to determine if post-testicular sperm maturation affects its expression and cellular distribution on spermatozoa. Additionally, we will investigate the effects of the blockade of sperm surface EPPIN with two anti-EPPIN antibodies that recognize epitopes in the N- (Q20E) and C- (S21C) terminal regions of this protein, respectively, on events associated with motility and capacitation, such as: 1) activated and hyperactivated motility, by CASA (Computer-assisted sperm analysis); 2) intracellular levels of AMPc, by AlphaScreen Assay; and 3) protein kinase A (PKA) phosphorylation by Western blot. Overall, this project will provide new insights into the roles of EPPIN on sperm function and foster its exploration as a drug target for male contraception. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SILVA, ALAN A. S.; RAIMUNDO, TAMIRIS R. F.; MARIANI, NOEMIA A. P.; KUSHIMA, HELIO; AVELLAR, MARIA CHRISTINA W.; BUFFONE, MARIANO G.; PAULA-LOPES, FABIOLA F.; MOURA, MARCELO T.; SILVA, ERICK J. R.. issecting EPPIN protease inhibitor domains in sperm motility and fertilizing ability: repercussions for male contraceptive developmen. MOLECULAR HUMAN REPRODUCTION, v. 27, n. 12, DEC 2021. (19/13661-1, 15/08227-0, 17/11363-8)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

SILVA, Alan Andrew dos Santos. Potential roles of EPPIN (Epididymal protease inhibitor) on post-testicular maturation of mouse spermatozoa: consequences for sperm function. 2021. Master's Dissertation - Universidade Estadual Paulista (Unesp). Instituto de Biociências. Botucatu Botucatu.