Dynamic Alterations in Testicular Autophagy in Prepubertal Mice

Autophagy has a potential regulatory effect on spermatogenesis and testicular development. Dynamic alterations in the testicular autophagy of prepubertal mice were analyzed, and the relationship between autophagy levels and testicular development was clarified using C57BL/6 mice aged 1, 2, 4, 6, and 8 weeks. Transmission electron microscopy was used to identify autophagic vacuoles. The expression of autophagy-related proteins and PI3K/AKT/mTOR signaling pathway-related proteins was determined using Western blotting. Localization of microtubule-associated protein light chain 3 (LC3) and sequestosome 1 (p62) in testicular tissues was determined using immunofluorescence and immunohistochemistry. Autophagic vacuoles in spermatogenic cells increased gradually from weeks 1 to 4, peaked at 2 weeks, decreased sharply at 6 weeks, and were undetectable at 8 weeks. The expression of Beclin 1 autophagy-related protein, LC3-II, and p62 was highest at 2 weeks among the five age groups, whereas LC3-II and p62 were mainly localized in spermatogonia and spermatocytes. Moreover, low mTOR expression and its increased expression were detected at 1-2 weeks and 2-8 weeks, respectively. These results show that testicular autophagic levels exhibit a dynamic pattern of "increase (1-2 weeks) followed by a decrease (2-8 weeks)," providing a reference in determining the relationship between autophagy levels and testicular development.