Underexpression of hsa-miR-449 family and their promoter hypermethylation in infertile men: A case-control study

Background: Post-transcriptional microRNAs (miRNAs) have a impotrant pattern in the spermatogenesis process.
Objective: Study of the expression and methylation of hsa-miR-449 family in sperm samples of infertile men.
Materials and Methods: In this case-control study, we recruited 74 infertile men (with asthenozoospermia, teratozoospermia, asthenoteratozoospermia, and oligoasthenoteratozoospermia) and 30 control samles. Methylation-specific PCR (MSP) method was used for methylation evaluation of hsa-miR-449 a, b, c promoter. By Real time PCR (qRT-PCR) method,we showed downregulation of hsa-miR-449 a, b, c in the sperm samples of infertile men and compared it to their fertile counterparts.
Results: There was significant underexperssion, in hsa-miR-449-b in oligoasthenoteratospermic samples (p = 0.0001, F = 2.9). About the methylation pattern, infertile men showed high frequency of methylation in the promoter of hsa-miR-449 a, b, c in comparison to controls (60.8% vs 23.3%), the highest amount of methylation was observed in oligoasthenoteratospermia samples (81.2%).
Conclusion: In this study, low expression and high methylation of hsa-miR-449-b were observed in infertile men in compared to control samples, which can be one of the causes of defective spermatogenesis.