Department of Histology and Embryology, Pomeranian Medical University in Szczecin, 70-111, Szczecin, Poland.
Department of Histology and Embryology, Pomeranian Medical University in Szczecin, 70-111, Szczecin, Poland.
Reprod Biol. 2021 Dec;21(4):100562. doi: 10.1016/j.repbio.2021.100562. Epub 2021 Sep 21.
The structural integrity of the germ cells in the seminiferous epithelium and the correct process of spermatogenesis are made possible by proteins that participate in the formation of different types of junctions. This study was performed on samples of the testes of 4 groups (2 experimental and 2 corresponding control) of male Wistar rats. In the first experimental group, the adult rats received letrozole - a nonsteroidal inhibitor of cytochrome P450 aromatase (P450arom). The second experimental group was exposed to soya isoflavones during the prenatal period, lactation, and up to sexual maturity. The aim of this study was to examine the immunoexpression of β-catenin, N-cadherin, occludin, connexin43, annexin V, and advanced glycation end products (AGE) in the seminiferous epithelium of rat testes with chronic estrogen deficiency and of rats exposed to soya isoflavones. Series of sections of the testes were stained using PAS and silver impregnation. Moreover, immunohistochemistry tests were performed. A semi-quantitative determination of protein immunoexpression was performed using Image J. The number of annexin V positive Sertoli cells per tubule were counted manually. Comparisons between the experimental and corresponding control groups were performed using a non-parametric Mann-Whitney U test. The most common alterations were prematurely sloughed germ cells in the lumen of the seminiferous tubules and invaginations of the seminiferous tubules. We observed a lower number of annexin V positive Sertoli cells and a lower expression of N-cadherin and occludin in the seminiferous epithelium of both groups of rats with hormonal imbalances. Moreover, a higher expression of AGE, a lower expression of connexin 43 and a lower amount of reticular fibers in the basal lamina of seminiferous tubules was present in rats treated with letrozole and a higher expression of β-catenin was found in rats exposed to soya isoflavones. The hormonal imbalance between androgens and estrogens resulted in a decreased number of annexin V positive Sertoli cells. This may be associated with a failed clearance of apoptotic germ cells that leads to disturbances in the blood-testis-barrier (BTB) by affecting the expression of junctional proteins in the seminiferous epithelium. Moreover, a decreased level of estrogens was also associated with an increased expression of AGEs and with a changed composition of basal lamina in the seminiferous tubules of rats. These changes could lead to germ cell sloughing and invaginations of the seminiferous tubules.
生精上皮中生殖细胞的结构完整性和精子发生的正确过程是由参与形成不同类型连接的蛋白质实现的。本研究对 4 组（2 个实验组和 2 个相应对照组）雄性 Wistar 大鼠的睾丸样本进行了研究。在第一实验组中，成年大鼠接受了来曲唑-一种非甾体细胞色素 P450 芳香酶（P450arom）抑制剂。第二实验组在产前、哺乳期和性成熟期间暴露于大豆异黄酮。本研究的目的是检测慢性雌激素缺乏和大豆异黄酮暴露的大鼠睾丸生精上皮中β-连环蛋白、N-钙粘蛋白、occludin、连接蛋白 43、膜联蛋白 V 和晚期糖基化终产物（AGE）的免疫表达。使用 PAS 和银染色对睾丸切片进行了一系列染色。此外，还进行了免疫组织化学测试。使用 Image J 对蛋白质免疫表达进行了半定量测定。手动计数每个小管中膜联蛋白 V 阳性支持细胞的数量。使用非参数 Mann-Whitney U 检验对实验组和相应对照组进行了比较。最常见的改变是生精小管管腔中过早脱落的生殖细胞和生精小管的内陷。我们观察到两组激素失衡大鼠的生精上皮中膜联蛋白 V 阳性支持细胞数量减少，N-钙粘蛋白和 occludin 的表达降低。此外，在接受来曲唑治疗的大鼠中，AGE 的表达增加，连接蛋白 43 的表达降低，生精小管基底层的网状纤维减少，在暴露于大豆异黄酮的大鼠中，β-连环蛋白的表达增加。雄激素和雌激素之间的激素失衡导致膜联蛋白 V 阳性支持细胞数量减少。这可能与未能清除凋亡的生殖细胞有关，通过影响生精上皮中连接蛋白的表达，导致血睾屏障（BTB）的破坏。此外，雌激素水平的降低也与 AGEs 的表达增加以及生精小管基底层组成的改变有关。这些变化可能导致生殖细胞脱落和生精小管的内陷。
