Bai Guang-Wei, Han Da-Yu, Yang Qi-Yun, Xie Yun, Guo Ze-Xin, Zhou Wen-Liang, Deng Chun-Hua, Sun Xiang-Zhou
Department of Urology and Andrology, The First Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, China.
School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong 510275, China.
Zhonghua Nan Ke Xue. 2019 Apr;25(5):302-308.
To investigate oxidative stress-mediated damage to the epididymal epithelial tight junction protein ZO-1 and its impact on epididymal function in varicocele rats.
We randomly divided 45 male adolescent SD rats into three groups of equal number: sham operation (left renal vein exposed and isolated), experimental (left renal vein constricted and collaterals of the left spermatic vein fully ligated), and treatment (60-day intragastric administration of vitamin E at 150 mg/kg/d after modeling). At 60 days after modeling, we observed the histological changes in the left epididymis, detected the expressions of ZO-1 and other tight junction-related proteins by real-time quantitative PCR, immunohistochemistry, immunofluorescence staining and Western blotting, determined sperm motility, and measured the levels of superoxide dismutase (SOD), total antioxidant capacity (T-AOC), methylene dioxyamphetamine (MDA) and α-glucosidase (α-Glu) in the epididymal tissue of the rats.
Compared with the rats of the sham operation group, those of the experimental group showed disorganized epithelial structure and decreased number of epithelial cells in the left epididymis, with some epithelial cells desquamated into the lumen. The expression of ZO-1 was significantly lower in the experimental than in the sham operation group (P < 0.05) but markedly upregulated after VE treatment (P < 0.05). In comparison with the sham operation group, the animals in the experimental group exhibited remarkably increased content of MDA in the epididymal tissue (［0.41 ± 0.05］ vs ［1.21 ± 0.18］ nmol/mg prot, P < 0.05) but decreased levels of SOD (［814.65 ± 73.64］ vs ［298.62 ± 67.84］ U/mg prot, P < 0.05), T-AOC (［0.84 ± 0.07］ vs ［0.24 ± 0.04］ nmol/mg prot, P < 0.05) and α-Glu (［11.72 ± 2.72］ vs ［5.82 ± 1.24］ U/mg prot, P < 0.05). VE treatment, however, remarkably reduced the content of MDA (［0.69 ± 0.12］ nmol/mg prot) and elevated the levels of SOD (［497.73 ± 48.03］ U/mg prot), T-AOC (［0.42 ± 0.06］ nmol/mg prot) and α-Glu (［9.11 ± 1.91］ U/mg prot) as compared with those in the experimental group (all P < 0.05). The percentage of progressively motile sperm was significantly lower in the experimental than in the sham operation group (［31.33 ± 6.32］% vs ［71.21 ± 5.21］%, P < 0.05), but markedly increased after VE treatment (［60.68 ± 5.31］%, P < 0.05).
Varicocele reduces the expression of the EETJ protein ZO-1 and impairs epididymal function via oxidative stress, while vitamin E can effectively upregulate the ZO-1 expression and improve epididymal function by decreasing oxidative stress in the epididymis of varicocele rats.
探讨氧化应激介导的附睾上皮紧密连接蛋白ZO - 1损伤及其对精索静脉曲张大鼠附睾功能的影响。
将45只雄性青春期SD大鼠随机分为3组，每组15只：假手术组（暴露并分离左肾静脉）、实验组（结扎左肾静脉并完全结扎左侧精索静脉分支）、治疗组（造模后以150 mg/kg/d的剂量灌胃维生素E 60天）。造模60天后，观察左侧附睾组织学变化，采用实时定量PCR、免疫组织化学、免疫荧光染色及蛋白质印迹法检测ZO - 1及其他紧密连接相关蛋白的表达，检测精子活力，并测定大鼠附睾组织中超氧化物歧化酶（SOD）、总抗氧化能力（T - AOC）、丙二醛（MDA）和α - 葡萄糖苷酶（α - Glu）水平。
与假手术组大鼠相比，实验组大鼠左侧附睾上皮结构紊乱，上皮细胞数量减少，部分上皮细胞脱入管腔。实验组ZO - 1表达明显低于假手术组（P < 0.05），维生素E治疗后显著上调（P < 0.05）。与假手术组相比，实验组大鼠附睾组织中MDA含量显著增加（［0.41 ± 0.05］比［1.21 ± 0.18］nmol/mg蛋白，P < 0.05），而SOD（［814.65 ± 73.64］比［298.62 ± 67.84］U/mg蛋白，P < 0.05）、T - AOC（［0.84 ± 0.07］比［0.24 ± 0.04］nmol/mg蛋白，P < 0.05）和α - Glu（［11.72 ± 2.72］比［5.82 ± 1.24］U/mg蛋白，P < 0.05）水平降低。然而，与实验组相比，维生素E治疗显著降低了MDA含量（［0.69 ± 0.12］nmol/mg蛋白），提高了SOD（［497.73 ± 48.03］U/mg蛋白）、T - AOC（［0.42 ± 0.06］nmol/mg蛋白）和α - Glu（［9.11 ± 1.91］U/mg蛋白）水平（均P < 0.05）。实验组精子前向运动百分比显著低于假手术组（［31.33 ± 6.32］%比［71.21 ± 5.21］%，P < 0.05），维生素E治疗后显著升高（［60.68 ± 5.31］%，P < 0.05）。
精索静脉曲张通过氧化应激降低附睾上皮紧密连接蛋白ZO - 1的表达并损害附睾功能，而维生素E可有效上调ZO - 1表达并通过降低精索静脉曲张大鼠附睾氧化应激来改善附睾功能。
