Department of Urology, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China.
Department of Gynaecology and Obstetrics, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China.
Mol Med Rep. 2017 Oct;16(4):5471-5479. doi: 10.3892/mmr.2017.7253. Epub 2017 Aug 16.
The present study aimed to determine the expression of autophagy and investigate whether the hypoxia‑inducible factor 1α (HIF‑1α)/BCL2 interacting protein (BNIP3)/Beclin‑1 autophagy signaling pathway serves an important role in activating autophagy in varicocele (VC) rat testes cells. Furthermore, the current study aimed to explain the possible association between autophagy and apoptosis. A total of 48 adult male Sprague Dawley rats were divided into group A (control), group B (VC 15‑day), group C (VC 30‑day) and group D (VC 45‑day), with 12 rats in each group. The rats in group A did not receive any interventions, and in groups B, C, and D the VC model was established simultaneously. At 0, 15, 30, and 45 days, an orchidectomy on the left testes was performed in groups A‑D, each on its respective day. Transmission electron microscopy was used to investigate the expression of autophagy. Compared with groups A and B, it was demonstrated that the expression of autophagy in groups C, and D was significantly increased. Hematoxylin and eosin staining revealed that as the rats survived VC longer, the testicular tissue damage became more serious. Furthermore, the Johnson score revealed that VC impaired the spermeiogenesis function of the male rats. Additionally, it was demonstrated that the apoptosis index of the semini-ferous epithelia cells in VC rat testes increased over time, as measured using TUNEL staining. Immunohistochemical analysis revealed that as the VC was prolonged, the expression of HIF‑1α gradually increased while the expression of (apoptosis regulator Bcl‑2) Bcl‑2 gradually decreased. Furthermore, western blot analysis revealed that the protein expression of Bcl‑2 decreased and apoptosis regulator Bax increased. Furthermore, HIF‑1α, BNIP3, Beclin1 and microtubule associated protein 1 light chain 3 α (LC3)II/LC3I expression gradually increased. However, significant increases in Beclin 1 and LC3II/LC3I were only observed between the day 0 and day 30 groups. In addition, the expression of p62 significantly increased between day 0 and day 15, but gradually decreased between day 15 and day 45. The results of the present study revealed that VC can lead to testicular tissue hypoxia, and that the HIF‑1α/BNIP3/Beclin1 autophagy signaling pathway may upregulate autophagy in VC rats testes. Thus, the association between autophagy and apoptosis may serve an important role in male infertility caused by VC.
本研究旨在探讨自噬的表达，并研究缺氧诱导因子 1α（HIF-1α）/BCL2 相互作用蛋白（BNIP3）/Beclin-1 自噬信号通路是否在精索静脉曲张（VC）大鼠睾丸细胞中激活自噬中发挥重要作用。此外，本研究旨在解释自噬与细胞凋亡之间的可能关联。将 48 只成年雄性 Sprague Dawley 大鼠分为 A 组（对照组）、B 组（15 天 VC 组）、C 组（30 天 VC 组）和 D 组（45 天 VC 组），每组 12 只大鼠。A 组大鼠不接受任何干预，B、C 和 D 组同时建立 VC 模型。在 0、15、30 和 45 天，对 A-D 组大鼠进行左侧睾丸切除术，每组在各自的日期进行。使用透射电子显微镜观察自噬的表达。与 A 组和 B 组相比，C 组和 D 组的自噬表达明显增加。苏木精-伊红染色显示，随着 VC 大鼠存活时间的延长，睾丸组织损伤变得更加严重。此外，Johnson 评分显示 VC 损害了雄性大鼠的精子发生功能。此外，使用 TUNEL 染色显示，随着时间的推移，VC 大鼠睾丸生精上皮细胞的细胞凋亡指数逐渐增加。免疫组织化学分析显示，随着 VC 的延长，HIF-1α的表达逐渐增加，而凋亡调节因子 Bcl-2 的表达逐渐减少。此外，Western blot 分析显示，Bcl-2 的蛋白表达减少，凋亡调节因子 Bax 增加。此外，HIF-1α、BNIP3、Beclin1 和微管相关蛋白 1 轻链 3α（LC3）Ⅱ/LC3I 的表达逐渐增加。然而，Beclin1 和 LC3Ⅱ/LC3I 仅在 0 天和 30 天组之间有显著增加。此外，p62 的表达在 0 天和 15 天之间显著增加，但在 15 天和 45 天之间逐渐减少。本研究结果表明，VC 可导致睾丸组织缺氧，HIF-1α/BNIP3/Beclin1 自噬信号通路可能上调 VC 大鼠睾丸中的自噬。因此，自噬与细胞凋亡之间的关联可能在 VC 引起的男性不育中发挥重要作用。
