title: Histone methylation and acetylation in ejaculated human sperm: effects of swim-up and smoking.
abstract: OBJECTIVE
  To assess global methylation and acetylation level before and after swim-up in ejaculated human sperm.
  
  
  METHODS
  Prospective experimental study.
  
  
  METHODS
  University-based hospital.
  
  
  METHODS
  Semen samples were obtained from 50 healthy volunteers (single sample per person) between December 2012 and May 2014.
  
  
  METHODS
  The semen samples were processed by the swim-up method.
  
  
  METHODS
  Sperm motility, strict morphology, DNA fragmentation index (DFI) by TUNEL, abnormal chromatin structure by toluidine blue staining, immunostaining of 8-hydroxy-2'-deoxyguanosine (8-OHdG) as an oxidative stress marker, immunostaining of 5-methyl-cytosine (5-mC) as a measurement of methylation level and immunostaining of six acetylation markers (H3K9ac, H3K14ac, H4K5ac, H4K8ac, H4K12ac, and H4K16ac) before and after swim-up.
  
  
  RESULTS
  After swim-up, motility and the percentage of normal form was significantly elevated. In the swim-up fraction, DFI and the percentage of abnormal chromatin structure were significantly lower and 8-OHdG levels were significantly higher. The 5-mC levels were significantly lower in the swim-up fraction, whereas no changes were observed in the positivity of six acetylation markers. Elevated percentage of normal form and decreased DFI and 5-mC levels were observed only in nonsmokers; 8-OHdG level was significantly higher in the swim-up fraction only from smokers. After swim-up, 5-mC levels were positively correlated with DFI.
  
  
  CONCLUSIONS
  This is the first study demonstrating decreased methylation and unchanged acetylation patterns in human sperm after swim-up preparation.
authors.affiliation: Department of Obstetrics and Gynecology, Seoul National University Bundang Hospital, Seongnam, South Korea; Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Seul Ki
authors.initials: SK
authors.lastname: Kim
authors.affiliation: Department of Obstetrics and Gynecology, Seoul National University Bundang Hospital, Seongnam, South Korea; Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, South Korea. Electronic address: blasto@snubh.org.
authors.forename: Byung Chul
authors.initials: BC
authors.lastname: Jee
authors.affiliation: Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, South Korea; Department of Obstetrics and Gynecology, Seoul National University Hospital, Seoul, South Korea.
authors.forename: Seok Hyun
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000107:Acetylation; D000328:Adult; D002469:Cell Separation / Q000379:methods; D002478:Cells, Cultured; D002498:Centrifugation; D053938:DNA Fragmentation; D019175:DNA Methylation / Q000502:physiology; D004542:Ejaculation / Q000502:physiology; D051548:Histone Acetyltransferases; D006657:Histones / Q000235:genetics*; D006801:Humans; D008297:Male; D012016:Reference Values; D055101:Semen Analysis; D012907:Smoking / Q000235:genetics*; D013048:Specimen Handling / Q000379:methods; D013081:Sperm Motility / Q000235:genetics*; D053625:Sperm Retrieval; D013094:Spermatozoa / Q000166:cytology / Q000502:physiology*
chemical_list: D006657:Histones; D051548:Histone Acetyltransferases
keywords: Spermatozoa; epigenomics; histone; methylation; smoking