尿激酶型纤溶酶原激活因子对小鼠获能精子线粒体膜电位的影响

目的:检测尿激酶型纤溶酶原激活因子(uPA)体外对小鼠获能精子线粒体膜电位的影响。方法:采用线粒体膜电位荧光染料JC-1,利用流式细胞仪和荧光显微镜检测分别与uPA(实验组)和BWW液(对照组)共孵育0、5、15、30、60min的小鼠获能精子线粒体膜电位状态。结果:①在uPA作用第5、15min时,精子体内平均荧光强度较作用前显著增加,高膜电位的精子数量百分率相应增加(P<0.05)。②与对照组相比,实验组在uPA作用5、15min时的高膜电位精子数量百分率,以及作用15、30、60min时的精子线粒体膜电位平均荧光强度显著增加(P<0.05)。结论:uPA在体外可以增加小鼠获能精子的线粒体膜电位,并使高膜电位状态维持一段时间,为获能精子提供充足的能量供应。

Effect of Urokinase-Type Plasminogen Activator on the Mitochondrial Membrane Potential of Mouse Capaciated-Spermatozoa in vitro

OBJECTIVE: To study the mechanism of uPA improving sperm capacitation by investigating the effect of uPA on the mitochondrial function of mouse capacitated-sperm in vitro. METHODS: Mitochondrial function of mouse capacitated-spermatozoa was evaluated through the assessment of mitochondrial membrane potential using JC-1 performed by flow cytometer and fluorescent microscope respectively. The experiment and the control groups were designed according to the presence or absence of uPA, each divided into 5 subgroups based on the different time of uPA treatment (or BWW in the control groups) at 0, 5, 15, 30 and 60 min respectively. RESULTS: (1) Compared with that at 0 min, the mean fluorescence intensity of JC-1 within the spermatozoal body and the percentage of orange-red colored spermatozoa in the experiment group were increased significantly at 5 and 15 min respectively after uPA incubation (P < 0.05). (2) The mean fluorescence intensity of JC-1 within the spermatozoal body at 15, 30 and 60 min and the percentage of orange-red colored spermatozoa at 5 and 15 min in the group were significantly higher than those in the control group (P < 0.05). CONCLUSION: uPA could increase the mitochondrial membrane potential of mouse capacitated-spermatozoa in vitro, and maintain it at a high level for a certain period of time. By enhancing sperm mitochondrial function, uPA may provide sufficient energy for capacitated-spermatozoa to increase their motility and change their motor pattern, which might be one of the therapeutic mechanisms of uPA on male infertility.