间充质干细胞对睾丸辐射损伤的影响

Mesenchymal stem cells on radiation-induced testicular injury

目的:研究间充质干细胞(MSCs)对睾丸辐射损伤的影响,为临床上治疗放射性睾丸损伤奠定理论基础。方法:选取15只雄性SD大鼠随机分为对照组、模型组和治疗组。模型组和治疗组大鼠均接受直线加速器产生的高能电子线行一次性全身照射;对照组不接受照射。治疗组大鼠接受辐射24h后尾静脉输注MSCs3×106/只;模型组和对照组大鼠尾静脉输注生理盐水1mL;共3周。当模型组处于濒死状态时处死所有大鼠,检测各组大鼠血清中睾酮水平、血清和睾丸组织中丙二醛(MDA)含量及超氧化物歧化酶(SOD)活性;采用苏木精-伊红染色法(HE染色法)制作大鼠的睾丸病理切片,观察辐射对睾丸形态学的影响。结果:模型组大鼠精神萎靡,反应迟钝,活动少,嗜睡,毛发变黄;治疗组大鼠较模型组反应灵敏。治疗组大鼠血清SOD明显高于模型组,而MDA水平低于模型组;治疗组大鼠血清睾酮含量明显高于模型组,但较正常组低。病理结果显示对照组生精小管横切面见精原细胞及不同发育阶段的精母细胞、精子细胞、精子,组成多种形态的完整生精上皮图像;模型组生精上皮变薄,生精层数减少,各级生精细胞明显减少,部分曲细精管内仅剩支持细胞和少量精原细胞,精子细胞及精子消失,显示辐射对大鼠睾丸组织损伤明显;治疗组外形较规则,各级生精细胞有序排列,初级精母细胞、精子细胞数量增多,精子发生良好,形态结构接近于对照组。结论:MSCs对睾丸的辐射损伤具有明显的修复作用,能够改善睾丸的生殖功能。

Objective To investigate the effect of mesenchymal stem cells （MSCs） on testis of rats with irradiation injury, and to provide the theoretical foundation of clinical treatment for radiation-induced testicular injury. Methods Fifteen male SD rats were randomly divided into 3 groups, namely control group, model group, and treatment group. Rats in the model group and treatment group received one-time total body irradiation with electron beam generated by high-energy linear accelerator line, 6 Gy per week, a total of 3 weeks, with cumulative total dose of 18 Gy; rats in the control group did not receive irradiation. Rats in the treatment group were performed intravenous infusion of MSCs of 3 x 106 cells 24 h after the irradiation; rats in model group and control group received intravenous infusion of normal saline of lmL. Rats were sacrificed, and the peripheral blood was collected. Serum level of testosterone, and malondialdehyde （MDA） content and superoxide dismutase enzyme （SOD） activity in serum and testicular tissues of each group were measured in the 3 groups; HE staining was employed to observe the morphology changes of the testicular tissues. Results Listlessness, lag in response, few activity, somnolence, and yellow hair were noted in rats in the model group; quick response in rats in the treatment group was found as compared with those in the model group. The serum level of SOD was obviously higher in the treatment group than that in the model group, while that of MDA was significantly lower. The serum level of testosterone in the treatment group was obviously higher than that in the model group, but was still lower than that in the control group. Pathology results indicated that spermatogenous cells, spermatocytes at different developmental stages, sperm cells, and spermatoblast were noted in the transection of seminiferous tubule of rats in the control group, constituting an intact imaging of spermatogenic epithelium. However, thinner spermatogenic epithelium, fewer layers of spermatogenic epithelium, decreased spermatogenous cells were noted in rat in the model group with few spermatogenous cells and supporting cells, indicating that testicular tissues were obviously damaged by irradiation. Spermatogenous cells, spermatocytes at different developmental stages, sperm cells and spermatoblast were noted in the transection of seminiferous tubule of rats in the treatment group, showing close morphological structure to the control group. Conclusion MSCs can repair the radiation-induced testicular injury in rats, and improve the reproductive function of testicle.