Genome-Wide microRNA Expression Profiling in Human Spermatozoa and Its Relation to Sperm Quality.

Background: Sperm samples are separated into bad and good quality samples in function of their phenotype, but this does not indicate their genetic quality.

Methods: Here, we used GeneChip miRNA arrays to analyze microRNA expression in ten semen samples selected based on high-magnification morphology (score 6 vs. score 0) to identify miRNAs linked to sperm phenotype.

Results: We found 86 upregulated and 21 downregulated miRNAs in good-quality sperm (score 6) compared with bad-quality sperm samples (score 0) (fold change > 2 and -value < 0.05). (FC × 30, = 8.43 × 10), (FC × 12, = 3.75 × 10), (FC × 8, = 0.0031), (FC × 5.6, = 0.0223), (FC × 4.83, = 0.0008) and (FC × 4, = 1.61 × 10) were among these upregulated miRNAs. In silico prediction algorithms predicted that miRNAs upregulated in good-quality sperm targeted 910 genes involved in key biological functions of spermatozoa, such as cell death and survival, cellular movement, molecular transport, response to stimuli, metabolism, and the regulation of oxidative stress. Genes deregulated in bad-quality sperm were involved in cell growth and proliferation.

Conclusions: This study reveals that miRNA profiling may provide potential biomarkers of sperm quality.