Giacomini Elisa, Ura Blendi, Giolo Elena, Luppi Stefania, Martinelli Monica, Garcia Rodolfo C, Ricci Giuseppe
Department of Medical, Surgical and Health Sciences, University of Trieste, Ospedale di Cattinara, Strada di Fiume 447, Trieste 34149, Italy.
Institute for Maternal and Child Health, IRCCS "Burlo Garofolo", Via dell'Istria 65/1, Trieste 34137, Italy.
Reprod Biomed Online. 2015 May;30(5):522-31. doi: 10.1016/j.rbmo.2015.01.010. Epub 2015 Jan 30.
A comparative proteomic study of oligoasthenozoospermic and normozoospermic seminal plasmas was conducted to establish differences in protein expression. Oligoasthenozoospermia (when semen presents with a low concentration and reduced motility of spermatozoa) is common in male infertility. Two-dimensional protein maps from seminal plasma samples from 10 men with normozoospermia and 10 men with idiopathic oligoasthenozoospermia were obtained by isoelectric focusing followed by sodium dodecyl-sulphate polyacrylamide electrophoresis. Map images were analysed using dedicated software involving normalization, spot-to-spot volume comparison and statistical treatment of the results to establish the significance of differences between normal and oligoasthenozoospermic samples. Six out of 1028 spots showed over 1.5-fold relative intensity differences (P < 0.05, analysis of variance). Four proteins were identified by nano liquid chromatography-electrospray ionization-mass spectrometry/mass spectrometry of their tryptic peptides and database searches. Two proteins were more than three-fold under-expressed in oligoasthenozoospermia, namely epididymal secretory protein E1 and galectin-3-binding protein; the other (lipocalin-1 and a prolactin-inducible protein form) were over-expressed. The identity and differential expression of epididymal secretory protein E1 was verified by Western-blotting. The statistically significant differential expression of these four proteins in oligoasthenozoospermia compared with normozoospermia provides a molecular basis for further investigations into the pathogenic mechanisms underlying idiopathic oligoasthenozoospermia.
为了确定蛋白质表达的差异，对少弱精子症和正常精子症的精浆进行了比较蛋白质组学研究。少弱精子症（精液中精子浓度低且活力降低）在男性不育中很常见。通过等电聚焦，然后进行十二烷基硫酸钠聚丙烯酰胺电泳，获得了10名正常精子症男性和10名特发性少弱精子症男性的精浆样本的二维蛋白质图谱。使用专门的软件对图谱图像进行分析，包括标准化、斑点间体积比较和结果的统计处理，以确定正常样本和少弱精子症样本之间差异的显著性。1028个斑点中有6个显示出超过1.5倍的相对强度差异（方差分析，P<0.05）。通过对其胰蛋白酶肽段进行纳升级液相色谱-电喷雾电离-质谱/质谱分析并检索数据库，鉴定出了4种蛋白质。两种蛋白质在少弱精子症中表达下调超过三倍，即附睾分泌蛋白E1和半乳糖凝集素-3结合蛋白；另外两种（脂质运载蛋白-1和一种催乳素诱导蛋白形式）则表达上调。通过蛋白质印迹法验证了附睾分泌蛋白E1的身份和差异表达。与正常精子症相比，这四种蛋白质在少弱精子症中具有统计学意义的差异表达，为进一步研究特发性少弱精子症的发病机制提供了分子基础。
