You have accessJournal of UrologyInfertility: Basic Research & Pathophysiology (MP38)1 Apr 2020MP38-12 ABNORMALLY METHYLATED LOCI IN TESTICULAR FIBROBLASTS FROM MEN WITH IDIOPATHIC NON-OBSTRUCTIVE AZOOSPERMIA ARE FLANKED BY SEQUENCES WITH HIGH HOMOLOGY TO PIRNAS Joseph Gabrielsen*, Larry Lipshultz, and Dolores Lamb Joseph Gabrielsen*Joseph Gabrielsen* More articles by this author , Larry LipshultzLarry Lipshultz More articles by this author , and Dolores LambDolores Lamb More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000887.012AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Over 1% of men lack sperm in the ejaculate due to impaired sperm production (non-obstructive azoospermia, NOA). The etiology remains unknown in the majority of cases. We defined abnormal patterns of DNA methylation in the testicular fibroblasts of these men (spermatogenic cells not present for analysis) compared with patterns present in the testicular fibroblasts of fertile control men, suggesting that aberrant gene regulation may be a contributing factor. How these genes are regulated—and specifically how this methylation is regulated—remains unknown. piRNAs affect gene methylation and are critical for spermatogenesis. Thus, the objective of this project was to test the hypothesis that piRNA binding sites are present in the regions flanking abnormal DNA methylation. METHODS: Discordant methylation sites were previously identified in NOA (n=21) and fertile (n=5) men. Using R Studio, the 50 base pairs of DNA flanking each site were automatically extracted from the human genome. Machine learning was then used to create dendrograms to cluster similar sequences by individual and these sequences were compared by Clustal Omega alignment. Cross referencing the sequences with over 35,000 known piRNA sequences was then performed requiring a minimum of 7 consecutive identical bases and allowing up to two mismatches per sequence. RESULTS: Men with NOA had between 4 and 41 discordantly hypermethylated sites. In each man, Clustal Omega alignment demonstrated high homology between specific subsets of the flanking DNA sequences. Sites were usually from different chromosomes, suggesting that abnormal methylation of the DNA may be regulated by factors binding the homologous regions. Regions flanking the hypermethylated DNA sites had high homology with piRNAs, indicating that aberrant expression of piRNAs may be contributing to abnormal methylation and, consequently, infertility in these men. CONCLUSIONS: Abnormally methylated DNA in testicular fibroblasts from men with NOA is often flanked by similar DNA sequences that share high homology with piRNAs. Future studies to understand how piRNAs are involved in DNA methylation, and how aberrant expression of piRNAs may lead to infertility may identify novel mechanisms for both diagnosing and treating this condition in the future. Source of Funding: JSG is supported in part by NIH K12 DK083014 Multidisciplinary K12 Urologic Research Career Development Program (to DJL) and by the Winfield Scott Charitable Trust. DJL is supported in part by the Frederick J. and Theresa Dow Wallace Fund of the New York Community Trust and R01DK078121 from the National Institutes of Health. © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e573-e574 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Joseph Gabrielsen* More articles by this author Larry Lipshultz More articles by this author Dolores Lamb More articles by this author Expand All Advertisement PDF downloadLoading ...