IRE1通路在染氟雄性大鼠生殖损伤中的作用*
Role of IRE1 pathway in fluoride-exposed male rat reproductive system injury

目的:探讨内质网应激IRE1通路在染氟雄性大鼠生殖系统中的作用。方法:60只4周龄SD雄性大鼠随机分为4组,包括对照组、NaF组、NAC组和NaF+NAC组,每组15只,采用等体积经口灌胃方式处理,每周灌胃6 d停灌1 d,连续灌胃7周。然后测定睾丸脏器系数,酶联免疫法测定血清中睾酮(T)、卵泡刺激素(FSH)、促黄体生成素(LH)含量,TUNEL法检测睾丸细胞凋亡情况,qRT-PCR法检测大鼠睾丸组织中IRE1及JNK mRNA的相对表达量,Western blot法检测大鼠睾丸组织中IRE1、p-IRE1、JNK和p-JNK蛋白的相对表达量。结果:与对照组相比,NaF组体重及睾丸质量减轻,血清T含量降低,血清FSH、LH含量升高,大鼠睾丸细胞凋亡指数升高,大鼠睾丸组织中IRE1及JNK mRNA表达水平均升高,p-IRE1及p-JNK蛋白表达水平均升高(P均＜0.05)。与NaF组比较,NaF+NAC组大鼠睾丸细胞凋亡指数降低,大鼠睾丸组织中IRE1及JNK mRNA表达水平均下降,p-JNK蛋白表达水平下降(P均＜0.05)。结论:氟暴露可以诱发内质网应激IRE1通路介导的JNK凋亡信号通路; NAC抑制内质网应激,对氟致雄性大鼠生殖损伤起到了一定的拮抗作用。
Aim: To research the role of IRE1 endoplasmic reticulum stress pathway in the fluoride-exposed male rat reproductive system injury.Methods: A total of sixty healthy male SD rats(4 weeks old)were divided into 4 groups randomly,including control group, NAC group, NaF group and NaF+NAC group. Each group had 15 rats. The rats were administered for 7 weeks,during which the rats were continuously treated by gavage for 6 days per week. Weight coefficient of testises was assayed. Testosterone(T), follicle stimulating hormone(FSH)and luteinizing hormone(LH)were determined by enzyme-linked immunosorbent assay. TUNEL method was used to detect testis cell apoptosis. IRE1 and JNK mRNA expression levels were detected by qRT-PCR. IRE1, p-IRE1, JNK and p-JNK protein expression levels were assayed by Western blot.Results: Compared with control group, in NaF group body weight and testicular weight were decreased, serum T level was decreased, serum FSH and LH levels were elevated, testicular apoptosis index was increased, the expression levels of IRE1 and JNK mRNA were increased, and protein expression levels of p-IRE1 and p-JNK were also increased significantly(P＜0.05). Compared with NaF group, in NaF+NAC group the apoptosis index was reduced, the expression levels of IRE1 and JNK mRNA were down-regulated, and protein expression level of p-JNK was decreased significantly(P＜0.05).Conclusion: Fluorine exposure could induce endoplasmic reticulum stress, and activate IRE1 mediated JNK apoptosis signaling pathway. NAC could inhibit endoplasmic reticulum stress, playing a protective role in fluoride-exposed male rat reproductive system injury