title: Analysis of the methylation pattern of six gene promoters in sperm of men with abnormal protamination.
abstract: It has recently been shown that alteration of the methylation pattern of imprinted genes is associated with different types of male infertility. The objective of our study was to investigate the methylation pattern of selected gene promoters in sperm of patients with abnormal protamine replacement. The promoters of OCT4, SOX2, NANOG, HOXC11, miR-17 and CREM were analyzed using bisulfite sequencing and the percentage of DNA methylation was compared between patients with an abnormal protamine 1/protamine 2 (P1/P2) ratio and normozoospermic controls. No significant quantitative differences were found between groups of patients with either an abnormally high or low P1/P2 ratio compared to normal controls. However, two individual samples from infertile subjects (2/20, 10%) showed an altered methylation pattern for the CREM gene promoter that was not found in control samples. These two samples had a significantly higher (P<0.05) promoter methylation (5.58 and 4.23%, respectively) compared to the control group (0.46%). In conclusion, in our pilot study, extreme methylations defects were not seen broadly in severely infertile men. However, two patients exhibited altered methylation of the CREM gene, which may be either causative or a result of abnormal protmaine replacement.
authors.affiliation: Andrology and IVF Laboratories, Department of Surgery, University of Utah School of Medicine, Salt Lake City, UT 84108, USA.
authors.forename: Laszlo
authors.initials: L
authors.lastname: Nanassy
authors.forename: Douglas T
authors.initials: DT
authors.lastname: Carrell
mesh_terms: D001483:Base Sequence; D051786:Cyclic AMP Response Element Modulator / Q000235:genetics; D019175:DNA Methylation; D017931:DNA Primers / Q000235:genetics; D044127:Epigenesis, Genetic; D018392:Genomic Imprinting; D018398:Homeodomain Proteins / Q000235:genetics; D006801:Humans; D007248:Infertility, Male / Q000235:genetics* / Q000378:metabolism*; D008297:Male; D035683:MicroRNAs / Q000235:genetics; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3 / Q000235:genetics; D010865:Pilot Projects; D011401:Promoter Regions, Genetic; D011479:Protamines / Q000378:metabolism*; D055748:SOXB1 Transcription Factors / Q000235:genetics; D013094:Spermatozoa / Q000378:metabolism*
chemical_list: C497410:CREM protein, human; D017931:DNA Primers; C484731:HOXC11 protein, human; D018398:Homeodomain Proteins; C524941:MIRN17 microRNA, human; D035683:MicroRNAs; C486780:NANOG protein, human; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; C082073:PRM1 protein, human; D011479:Protamines; C527782:SOX2 protein, human; D055748:SOXB1 Transcription Factors; C068621:protamine 2; D051786:Cyclic AMP Response Element Modulator