Qu Wenjia, Tarique Imran, Deng Bihua, Zhang Yue, Haseeb Abdul, Chen Quisheng, Yang Ping
MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu Province, 210095, China.
Institute of Veterinary Immunology and Engineering, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu Province, 210014, China.
Theriogenology. 2020 Sep 15;154:237-245. doi: 10.1016/j.theriogenology.2020.05.024. Epub 2020 May 22.
Sertoli cells (SCs) play their nursing role as structural and functional supporting cells during spermatogenesis to ensure the production of highly specialized mature spermatozoa. Besides that, the role of SCs in autophagy during active (adult) and inactive (young) spermatogenesis in the caprine testis is still largely unknown. In this study, we investigated autophagy in goat SCs by light microscopy, immunohistochemistry (IHC), double immunofluorescence (double-IF), and transmission electron microscopy. Light microscopy showed active seminiferous tubules with SCs and layers of developing germ cells in the adult goat testis. In young goats, layer of germ cells and SCs was viewed on the basal membrane in the seminiferous tubule. IHC of autophagy-related 7 (ATG7) showed moderate expressions in the cytoplasmic extensions of SCs during inactive spermatogenesis, and strong expression was observed during active spermatogenesis in the testis of goat. Co-immunolabeling of p62 or light chain 3 (LC3) with vimentin showed increasing expression from the basal to the luminal compartment of the seminiferous tubule and stronger expression during active than inactive spermatogenesis in the testis of goat. Ultrastructure assessment of the cytoplasm in SCs showed phagophores, generated from the endoplasmic reticulum during active spermatocytogenesis. Numerous autophagosomes and autolysosomes were noted in the SCs cytoplasm, which surrounds the spermatogenic cells in the basal compartment of the seminiferous tubules. At a later stage, SCs showed autophagosomes and autolysosomes, together with multivesicular bodies (MVB), during spermiogenesis at different phases of the acrosome formation. Numerous embedded elongated spermatozoa were found in the cytoplasm of SCs, surrounded by autophagic components and MVB. Under TEM, the mean diameter of autophagosomes was 952.35 nm and that of autolysosomes was 504.38 nm. Collectively, these results suggest that autophagy is active in SCs during caprine spermatogenesis and that the level of autophagy becomes more evident as spermatogenesis advances from the basal to the luminal compartment of SC.
支持细胞（SCs）在精子发生过程中作为结构和功能上的支持细胞发挥其滋养作用，以确保产生高度特化的成熟精子。除此之外，在山羊睾丸活跃（成年）和不活跃（幼年）精子发生过程中，支持细胞在自噬中的作用仍 largely 未知。在本研究中，我们通过光学显微镜、免疫组织化学（IHC）、双免疫荧光（双 IF）和透射电子显微镜研究了山羊支持细胞中的自噬。光学显微镜显示成年山羊睾丸中有活跃的生精小管，其中有支持细胞和发育中的生殖细胞层。在幼年山羊中，在生精小管的基底膜上可见生殖细胞层和支持细胞。自噬相关 7（ATG7）的免疫组织化学显示，在不活跃精子发生过程中，支持细胞的细胞质延伸中有中度表达，而在山羊睾丸的活跃精子发生过程中观察到强表达。p62 或轻链 3（LC3）与波形蛋白的共免疫标记显示，从生精小管的基底到管腔部分表达增加，且在山羊睾丸中活跃精子发生期间的表达强于不活跃精子发生期间。对支持细胞细胞质的超微结构评估显示，在活跃的精母细胞发生过程中，内质网产生吞噬体。在支持细胞的细胞质中发现了许多自噬体和自溶酶体，它们围绕着生精小管基底部分的生精细胞。在后期，在顶体形成的不同阶段的精子形成过程中，支持细胞显示出自噬体、自溶酶体以及多囊泡体（MVB）。在支持细胞的细胞质中发现了许多嵌入的细长精子，周围有自噬成分和 MVB。在透射电子显微镜下，自噬体的平均直径为 952.35nm，自溶酶体的平均直径为 504.38nm。总的来说，这些结果表明在山羊精子发生过程中支持细胞中的自噬是活跃的，并且随着精子发生从支持细胞的基底向管腔部分推进，自噬水平变得更加明显。
