Sperm DNA fragmentation index (SDF), as an important supplement to routine semen parameters, has been proposed to discriminate between fertile and infertile men, and predicts the outcomes of natural conception and in vitro fertilization. Unfortunately there are uncertainty and contradictory evidences regarding the importance of SDF. An important reason is the fact that significant and fundamental research about SDF is rare. This study was designed to characterize the microRNA (miRNA) expression profile in seminal plasma of normospermic patients with different SDF and their implications in human fertility. Using next-generation sequencing (NGS), a total of 897 human miRNAs were detected from 10 seminal plasma samples, out of which 431 differentially expressed miRNAs in 5 pairs of seminal plasma samples (each pair of seminal plasma samples obtained from the same male), with 14 miRNAs were identified in all the pairs. According to the fold change and expression level, 7 miRNAs including miR-374b-5p, miR-429, hsa-miR-26b-5p, miR-21-5p, miR-4257, miR-135b-5p and miR-134-5p were selected for further excavation. MiR-374b-5p and miR-26b-5p were significantly different in 3 sets of individual seminal plasma samples with different SDF from total 90 infertile patients (30 patients each set). Our results demonstrate that the profile of miR-374b and miR-26b with significantly decreased expression could be used as a first indication of increased SDF. And miR-374b and miR-26b could serve as adjunct biomarkers for the diagnosis of idiopathic infertile males.

中文翻译：

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不同精子DNA片段化指数的常精患者精浆中微RNA的差异表达。

精子DNA断裂指数（SDF）作为常规精液参数的重要补充，已被提议用来区分可育和不育男性，并预测自然受孕和体外受精的结果。不幸的是，关于SDF的重要性存在不确定性和矛盾的证据。一个重要的原因是关于SDF的重要而基础的研究很少。这项研究旨在表征具有不同SDF的常精患者精浆中microRNA（miRNA）的表达谱及其对人类生育力的影响。使用下一代测序（NGS），从10个精浆血浆样品中总共检测到897个人类miRNA，在5对精子血浆样品（每对精子血浆样品均来自同一雄性）中，其中431种差异表达的miRNA，在所有对中均鉴定出14种miRNA。根据倍数变化和表达水平，包括miR-374b-5p，miR-429，hsa-miR-26b-5p，miR-21-5p，miR-4257，miR-135b-5p和miR-134-选择5便士进行进一步挖掘。在总共90例不育患者（每组30例）中，三组具有不同SDF的精浆血浆中的MiR-374b-5p和miR-26b-5p显着不同。我们的结果表明，表达显着降低的miR-374b和miR-26b谱可作为SDF增加的第一个指征。miR-374b和miR-26b可以作为诊断特发性不育男性的辅助生物标志物。