Distribution of DNA damage in the human sperm nucleus:implications of the architecture of the sperm head  

作　　者：Silvia González-Rojo Cristina Fernández-Díez Marta Lombó María Paz Herráez 

机构地区：[1]Department of Molecular Biology,Faculty of Biology,Universidad de León,Campus de Vegazana s/n León,León 24071,Spain

出　　处：《Asian Journal of Andrology》2020年第4期401-408,共8页亚洲男性学杂志（英文版）

基　　金：the Spanish Ministry of Economy and Competitiveness(project AGL2011-27787,AGL2014-53167-C3-3-R);Junta de Castilla y Leon(Spain)(EDU/1083/2013)and Fondo Social Europeo.

摘　　要：The sperm nucleus is prone to sustain DNA damage before and after ejaculation.Distribution of the damage is not homogeneous,and the factors determining differential sensitivity among nuclear regions have not yet been characterized.Human sperm chromatin contains three structural domains,two of which are considered the most susceptible to DNA damage:the histone bound domain,harboring developmental related genes,and the domain associated with nuclear matrix proteins.Using a quantitative polymerase chain reaction(qPCR)approach,we analyzed the number of lesions in genes homeobox A3(HOXA3),homeobox B5(HOXB 5),sex-determining region Y(SRY)-box 2(SOX2),β-GLOBIN,rDNA 18S,and rDNA 28S in human sperm after ultraviolet irradiation(400μW cm−2,10 min),H2O2treatment(250 mmol l−1,20 min),and cryopreservation,which showed differential susceptibility to genetic damage.Differential vulnerability is dependent on the genotoxic agent and independent of the sperm nuclear proteins to which the chromatin is bound and of accessibility to the transcription machinery.Immunodetection of 8-hydroxy-2'-deoxyguanosine(8-OHdG)showed that the highest level of oxidation was observed after H2O2treatment.The distribution of oxidative lesions also differed depending on the genotoxic agent.8-OHdG did not colocalize either with histone 3(H3)or with type IIα+βtopoisomerase(TOPO IIα+β)after H2O2treatment but matched perfectly with peroxiredoxin 6(PRDX6),which is involved in H2O2metabolism.Our study reveals that the characteristics of the sperm head domains are responsible for access of the genotoxicants and cause differential degree of damage to nuclear areas,whereas chromatin packaging has a very limited relevance.The histone-enriched genes analyzed cannot be used as biomarkers of oxidative DNA damage.

关 键 词：biomarkers DNA damage human sperm oxidative stress sperm chromatin sperm quality 

分 类 号：Q523[生物学—生物化学] R697[医药卫生—泌尿科学]