Association between Sperm Morphology and Altered Sperm microRNA Expression

Area of Science:

• Reproductive Biology
• Molecular Biology
• Genetics

Background:

• Semen analysis, the traditional method for evaluating male infertility, can be subjective.
• There is a growing need for stable, quantifiable biomarkers to assess sperm quality.
• MicroRNAs (miRNAs) are emerging as potential indicators of various biological states.

Purpose of the Study:

• To investigate the differential expression of specific miRNAs in spermatozoa of men with teratozoospermia compared to normozoospermic individuals.
• To identify potential miRNA biomarkers for sperm morphology and in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcomes.

Main Methods:

• Quantitative real-time polymerase chain reaction (qPCR) was used to analyze the expression levels of 13 candidate miRNAs in spermatozoa.
• Participants were divided into a control group (normozoospermic males) and a study group (males with teratozoospermia) undergoing IVF/ICSI.
• Sperm morphology and IVF/ICSI cycle outcomes were correlated with miRNA expression profiles.

Main Results:

• Nine miRNAs (miR-10a-5p, miR-15b-5p, miR-26a-5p, miR-34b-3p, miR-122-5p, miR-125b-5p, miR-191-5p, miR-296-5p, and let-7a-5p) were significantly underexpressed in spermatozoa from men with teratozoospermia.
• The expression levels of these nine miRNAs were positively correlated with sperm morphology.
• Only miR-99b-5p expression showed a significant positive correlation with good-quality day 3 embryo rate in the IVF/ICSI cycle.

Conclusions:

• The study identified nine miRNAs that are significantly underexpressed in teratozoospermia and correlate with sperm morphology.
• These miRNAs hold promise as objective biomarkers for assessing sperm quality and potentially predicting IVF/ICSI success.
• This research contributes to the development of more reliable diagnostic tools for male infertility.