Aoki Vincent W, Emery Benjamin R, Liu Lihua, Carrell Douglas T
Andrology/IVF, University of Utah School of Medicine, Salt Lake City, UT 84108, USA.
J Androl. 2006 Nov-Dec;27(6):890-8. doi: 10.2164/jandrol.106.000703. Epub 2006 Jul 26.
Sperm protamine deficiency has been associated with human male infertility. However, most studies have adopted a global approach to assessing sperm protamine levels. Thus, it is not known whether sperm cells from individual human males possess variations in protamine protein content. The objectives of this study were to evaluate variations in protamine-1 (P1) and protamine-2 (P2) content between individual sperm cells of fertile and infertile men and to correlate DNA integrity and sperm cell viability with protamine levels in individual sperm cells. The semen samples of fertile and infertile men were evaluated globally for protamine protein content using nuclear protein extraction, gel electrophoresis, and densitometry analysis. Individual sperm cell P1 and P2 levels were assessed using immunofluorescence microscopy in conjunction with automated image analysis. The terminal transferase dUTP nick end labeling (TUNEL) assay was performed simultaneously with protamine immunostaining to assess the relationship between protamine levels and DNA integrity in individual spermatozoa. Additionally, the relationship between sperm cell viability and protamine levels was assessed via viability staining concomitant with protamine staining. The protamine fluorescence data demonstrate significant variations in protamine content within individual sperm cells of human males. Overall population-based measures of DNA integrity and sperm cell viability correlate significantly with population-based measurements of protamine levels. The data also demonstrate individual sperm cells displaying the lowest protamine levels display diminished viability and increased sperm cell susceptibility to DNA damage.
精子鱼精蛋白缺乏与人类男性不育有关。然而，大多数研究采用整体方法来评估精子鱼精蛋白水平。因此，尚不清楚来自个体男性的精子细胞在鱼精蛋白含量上是否存在差异。本研究的目的是评估可育和不育男性个体精子细胞之间鱼精蛋白-1（P1）和鱼精蛋白-2（P2）含量的差异，并将DNA完整性和精子细胞活力与个体精子细胞中的鱼精蛋白水平相关联。使用核蛋白提取、凝胶电泳和光密度分析对可育和不育男性的精液样本进行整体鱼精蛋白含量评估。结合自动图像分析，使用免疫荧光显微镜评估个体精子细胞的P1和P2水平。在进行鱼精蛋白免疫染色的同时进行末端脱氧核苷酸转移酶dUTP缺口末端标记（TUNEL）试验，以评估个体精子中鱼精蛋白水平与DNA完整性之间的关系。此外，通过与鱼精蛋白染色同时进行的活力染色来评估精子细胞活力与鱼精蛋白水平之间的关系。鱼精蛋白荧光数据表明，人类男性个体精子细胞中的鱼精蛋白含量存在显著差异。基于总体人群的DNA完整性和精子细胞活力测量与基于总体人群的鱼精蛋白水平测量显著相关。数据还表明，鱼精蛋白水平最低的个体精子细胞活力降低，对DNA损伤的易感性增加。
