RESUMEN
Sperm histones represent an essential part of the paternally transmitted epigenome, but uncertainty exists about the role of those remaining in non-coding and repetitive DNA. We therefore analyzed the genome-wide distribution of the heterochromatic marker H4K20me3 in human sperm and somatic (K562) cells. To specify the function of sperm histones, we compared all H4K20me3-containing and -free loci in the sperm genome. Sperm and somatic cells possessed a very similar H4K20me3 distribution: H4K20me3 peaks occurred mostly in distal intergenic regions and repetitive gene clusters (in particular genes encoding odorant-binding factors and zinc-finger antiviral proteins). In both cell types, H4K20me3 peaks were enriched in LINEs, ERVs, satellite DNA and low complexity repeats. In contrast, H4K20me3-free nucleosomes occurred more frequently in genic regions (in particular promoters, exons, 5'-UTR and 3'-UTR) and were enriched in genes encoding developmental factors (in particular transcription activators and repressors). H4K20me3-free nucleosomes were also detected in substantial quantities in distal intergenic regions and were enriched in SINEs. Thus, evidence suggests that paternally transmitted histones may have a dual purpose: maintenance and regulation of heterochromatin and guidance towards transcription of euchromatin.
Asunto(s)
Histonas/genética , Secuencias Repetitivas de Ácidos Nucleicos/genética , Espermatozoides/fisiología , Regiones no Traducidas 3'/genética , Regiones no Traducidas 5'/genética , Línea Celular Tumoral , ADN/genética , Exones/genética , Genoma/genética , Heterocromatina/genética , Humanos , Células K562 , Masculino , Nucleosomas/genética , Regiones Promotoras Genéticas/genética , Factores de Transcripción/genética , Transcripción Genética/genéticaRESUMEN
Background/Aims/Objectives: Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) has detrimental effects on the quality of life including the aspect of sexual dysfunction. The aim of the study was to identify if there was an adverse effect on the male genital compartment and if there are systemic or compartment-specific local signals for epigenetic dysregulation of inflammatory factors in CP/CPPS patients. METHODS: One hundred five NIH IIIb CP/CPPS patients and 41 healthy men were recruited and underwent investigations of urines, semen and blood. Promoter methylation and expression of the chemokine C-X-C motif chemokine 12 and its receptor C-X-C chemokine receptor type 4 (CXCR4) (involved in the recruitment of mast cells) were analyzed in prostate epithelial cell lines and in healthy volunteers' and patients' blood, ejaculate cell pellets, and separated ejaculate fractions (sperm and seminal somatic cells). RESULTS: Independently from age, CP/CPPS NIH IIIb was associated with significant impairment of sperm motility, morphology and semen pH (p < 0.001). Patients older than 33 years showed significantly increased seminal interleukin-8 and serum prostate specific antigen values. In patients, the CXCR4 mRNA-expression was significantly decreased in whole blood and ejaculate cell pellets due to promoter hypermethylation. Analyses on separated fractions of sperm and seminal somatic cells revealed that sperm DNA was unaffected, whereas somatic cell DNA was differentially methylated. CONCLUSIONS: NIH IIIb CP/CPPS has negative effects on surrogate parameters of male fertility and is associated significantly with systemic and local epigenetic inactivation of CXCR4.