视黄酸对隐睾生精细胞增殖分化及减数分裂的作用及其机制研究

目的 探讨视黄酸对隐睾生精细胞增殖分化及减数分裂的作用及其机制。方法 将30 只SD 孕鼠随机分为3 组，每组10 只，取子代雄鼠进行研究。对照组常规饲养不给任何药物或试剂；模型组采用雄激素拮抗剂氟他胺（Flu）复制隐睾大鼠模型；干预组在模型组基础上，在子代雄鼠生精细胞发育时期予以视黄酸干预。采用TUNEL 法检测生精细胞的凋亡，免疫组织化学法观察睾丸组织中c-Kit、Stra8、Scp3 蛋白的表达，qRT-PCR 检测睾丸组织中Stra8、c-Kit、Scp3 mRNA 的表达，Western blotting 检测睾丸组织中Stra8、Scp3、c-Kit 和PLZF 蛋白的表达。结果 免疫组织化学结果显示，对照组和干预组中可见大量精子细胞排列整齐；而模型组睾丸各级生精细胞数目减少、排列紊乱，且曲细精管管腔缩窄。TUNEL 检测结果显示，与对照组和干预组比较，模型组可见大量生精细胞凋亡。对照组和干预组凋亡指数低于模型组（P <0.05）。对照组和干预组Stra8、c-Kit、Scp3 mRNA 和蛋白相对表达量高于模型组（P <0.05）。对照组和干预组PLZF 蛋白相对表达量高于模型组（P <0.05）。结论 视黄酸促进生精细胞发育的作用机制可能与调控隐睾生精细胞增殖分化及减数分裂有关，可一定程度上恢复隐睾大鼠的生殖功能。

Effects of retinoic acid on the proliferation, differentiation andmeiosis of spermatogenic cells in cryptorchidismand its mechanism

Objective To study the effect of retinoic acid (RA) on the proliferation, differentiation and meiosisof spermatogenic cells in cryptorchidism and its mechanism. Methods The offspring of male SD rats were used forthe study. The normal control group did not receive any drugs or reagents, Flu cryptorchidism group was induced byandrogen antagonist flutamide (Flu), RA intervention group was given retinoic acid intervention during spermatogeniccell development. The spermatogenic cell apoptosis was detected by TUNEL; the expression of Stra8, Scp3 andc-Kit protein in testis tissue was observed by immunohistochemistry; the mRNA levels of Stra8, c-Kit and PLZF in testicular tissue were detected by RT-qPCR; the expression of Stra8, Scp3, c-Kit and PLZF protein in testicular tissuewas detected by Western blotting. Results Pathological examination showed that a large number of sperm cells werefound in the normal control group and RA intervention group, and the germ cells in all layers were arranged regularly.However, the number of germ cells at all levels in the testis of Flu cryptorchidism group was reduced and disordered,and the lumen of seminiferous tubules was significantly narrowed. TUNEL assay showed that a large numberof spermatogenic cells were apoptosis in flu cryptorchidism group compared with normal control group and RAintervention group. Compared with the flu model group, the apoptosis index of the control group and RA interventiongroup was lower (P < 0.05). Compared with the flu cryptorchidism group, the expression levels of Stra8, c-Kit, Scp3mRNA and protein were higher in the control group and RA intervention group (P < 0.05). Compared with the flucryptorchidism group, the PLZF protein expression level in the control group and RA intervention group was higher(P < 0.05). Conclusions The mechanism of retinoic acid promoting spermatogenic cell development may be relatedto regulating the meiotic differentiation and proliferation of cryptorchidism spermatogenic cells, which restores thereproductive function of cryptorchidism rats to a certain extent.