ERp57 is a potential biomarker for human fertilization capability

Area of Science:

• Reproductive Biology
• Molecular Biology
• Andrology

Background:

• Human infertility affects many couples, with assisted reproductive technologies (ART) having limited success rates.
• Predictive tests for ART outcomes are significant, potentially involving proteins essential for fertilization.

Purpose of the Study:

• To identify proteins involved in human fertilization.
• To investigate the role of ERp57 in sperm function and its potential as a marker for male infertility.

Main Methods:

• Two-dimensional polyacrylamide gel electrophoresis and MALDI-TOF for protein identification.
• Immunohistochemistry to determine ERp57 localization in human testes and spermatozoa.
• Functional assays involving antibody blockade of ERp57 and assessment of sperm-oocyte penetration.
• Correlation analysis of ERp57 expression levels with fertility outcomes in In Vitro Fertilization (IVF) patients.

Main Results:

• ERp57 protein was identified in human testis protein profiles.
• ERp57 is localized in spermatogenic cells, Leydig cells, and human spermatozoa (acrosome and tail), translocating post-acrosome reaction.
• ERp57 undergoes post-translational modification during sperm capacitation.
• Antibody-mediated blockade of ERp57 significantly inhibited sperm penetration of oocytes.
• Reduced ERp57 expression levels were observed in IVF patients with low fertilization rates compared to fertile individuals.

Conclusions:

• ERp57 is a key component of human sperm acrosome proteins essential for gamete fusion.
• ERp57 expression levels are associated with male fertility.
• ERp57 represents a potential novel biomarker for male infertility and for sperm selection in IVF.