Central Laboratory, Yantai Yu Huang Ding Hospital/Qingdao University, Yantai 264000, Shandong, P.R. China.
Central Laboratory, Yantai Yu Huang Ding Hospital/Qingdao University, Yantai 264000, Shandong, P.R. China
Hum Reprod. 2015 Apr;30(4):861-9. doi: 10.1093/humrep/dev003. Epub 2015 Jan 29.
Does a defect in the human sperm-located protein prostate and testis expressed 1 (PATE1) exist in both aged men and young asthenozoospermia patients?
A defect in sperm PATE1 exists in both aged men and young asthenozoospermia patients, and an antibody against PATE1 can decrease human sperm motility and zona-free hamster oocyte penetration.
Both aged men and young asthenozoospermia patients have poor sperm quality. The PATE1 protein seems to mediate sperm-egg interactions; however, the mechanisms are still unknown.
STUDY DESIGN, SIZE, DURATION: This was a case-control study including 60 young fathers (aged 28-32 years) and 60 aged fathers (68-72 years old) who donated semen by masturbation after 7 days of sexual abstinence. Comparative sperm proteome analysis from the young fathers and aged fathers was performed to discover key proteins. The target protein PATE1 was chosen and validated by western blotting and immunohistochemistry. Quantitative assessment of sperm PATE1 protein was performed on sperm from 60 young fathers, 60 aged fathers and 110 young asthenozoospermia patients. Furthermore, an antibody against PATE1 assay was used to test whether PATE1 participated in sperm motility and penetration of zona-free hamster egg.
PARTICIPANTS/MATERIALS, SETTING, METHODS: Samples were pooled and separated by two-dimensional gel electrophoresis followed by identification by matrix-assisted laser desorption/ionization time of flight mass spectrometry. Western blotting and immunohistochemistry were used to validate the confidence of proteomic data. Sperm immunofluorescence quantification experiments disclosed whether the aged men indeed shared the same PATE1 defect with 110 young asthenozoospermia patients. The sperm motility test and penetration of zona-free hamster egg assay were performed for PATE1.
Twenty-two sperm proteins with significant differential expression between young adults and aged men were identified (P < 0.05, mean ratio >1.5), including 13 proteins with decreased expressions with aging. Based on bioinformatics, PATE1 was chosen for further study, and exhibited similar changes in expression level and localization on sperm from aged men and young asthenozoospermia patients. Antibody blocking revealed that PATE1 was involved in sperm-egg penetration and sperm motility.
LIMITATIONS, REASONS FOR CAUTION: Before any clinical application of PATE1 as a biomarker for the diagnosis of male infertility, more cases should be used to evaluate confidence in this approach.
This study revealed a common molecular basis underlying the decline in sperm quality in the natural aging process and in young men with asthenozoospermia. The data should greatly contribute to the development of molecular evaluation of sperm quality, and the diagnosis and treatment of asthenozoospermia.
STUDY FUNDING/COMPETING INTERESTS: This work was supported by grants from the National Natural Science Foundation of China (NO. 81300533, 81370013 and 81000277) and Shandong Provincial Natural Science Foundation, China (ZR2013HQ002, ZR2014HQ068). The authors declare no competing financial interests.
人类精子定位蛋白前列腺和睾丸表达 1（PATE1）是否存在于老年男性和年轻弱精子症患者中？
精子 PATE1 缺陷存在于老年男性和年轻弱精子症患者中，针对 PATE1 的抗体可降低人类精子的运动能力并穿透去透明带仓鼠卵。
老年男性和年轻弱精子症患者的精子质量都较差。PATE1 蛋白似乎介导了精子-卵子相互作用，但机制尚不清楚。
研究设计、大小、持续时间：这是一项病例对照研究，纳入了 60 名年轻父亲（年龄 28-32 岁）和 60 名老年父亲（68-72 岁），他们在禁欲 7 天后通过自慰捐献精液。对年轻父亲和老年父亲的比较精子蛋白质组分析用于发现关键蛋白质。选择靶蛋白 PATE1 并通过 Western blot 和免疫组织化学进行验证。对 60 名年轻父亲、60 名老年父亲和 110 名年轻弱精子症患者的精子进行定量评估 PATE1 蛋白。此外，还使用针对 PATE1 的抗体检测 PATE1 是否参与精子运动和穿透去透明带仓鼠卵。
参与者/材料、设置、方法：将样本混合并通过二维凝胶电泳分离，然后通过基质辅助激光解吸/电离飞行时间质谱进行鉴定。Western blot 和免疫组织化学用于验证蛋白质组数据的可信度。精子免疫荧光定量实验揭示了老年男性是否确实与 110 名年轻弱精子症患者存在相同的 PATE1 缺陷。针对 PATE1 进行精子运动测试和穿透去透明带仓鼠卵实验。
在年轻成年人和老年男性之间鉴定出 22 种具有显著差异表达的精子蛋白（P <0.05，平均比值>1.5），其中包括 13 种随着年龄增长表达减少的蛋白。基于生物信息学，选择 PATE1 进行进一步研究，发现其在老年男性和年轻弱精子症患者的精子中的表达水平和定位均发生了相似的变化。抗体阻断表明 PATE1 参与了精子-卵子穿透和精子运动。
局限性、谨慎的原因：在将 PATE1 作为男性不育诊断的生物标志物进行任何临床应用之前，应该使用更多的病例来评估这种方法的可信度。
这项研究揭示了自然衰老过程中精子质量下降和年轻弱精子症男性精子质量下降的共同分子基础。该数据将极大地促进精子质量的分子评估以及弱精子症的诊断和治疗的发展。
研究资金/竞争利益：本工作得到国家自然科学基金（NO.81300533、81370013 和 81000277）和山东省自然科学基金（ZR2013HQ002、ZR2014HQ068）的支持。作者声明没有竞争利益。
