Association of the patterns of global DNA methylation and expression analysis of DNA methyltransferases in impaired spermatogenic patients

Objective: To analyze global DNA methylation along with DNA methyltransferases (DNMTs) expression at transcript level in patients with impaired spermatogenesis to dissect its role in pathophysiology of human male infertility. Method: The content of Global methylated cytosine (mC) was determined using ELISA system (Imprint Methylated DNA Quantification Kit, Sigma–Aldrich) in 31 testicular biopsies showing impaired spermatogenesis and 8 with normal spermatogenesis. Real-time reverse transcription-polymerase chain reaction was done to analyze DNMTs (DNMT1, DNMT3A, DNMT3B and DNMT3L) mRNA levels in biopsies with different testicular phenotypes. Results: There was significant increase in levels of global methylation in different impaired testicular phenotypes as compared to normal. Expression analysis revealed significantly increased expression of DNMT1 and its positive correlation with global DNA methylation. Conclusion: In conclusion, increased levels of global methylation in impaired cases might be the one of the contributing factors for aberrant gene expression in infertile patients.