Cathepsin B plays a role in spermatogenesis and sperm maturation through regulating autophagy and apoptosis in mice

Spermatogenesis and sperm maturation are complex and highly ordered biological processes. Any failure or disorder in these processes can cause defects in sperm morphology, motility, and fertilization ability. Cathepsin B (CTSB) is involved in the regulation of a variety of pathological processes. In the present study, we found that CTSB was abundantly expressed in the male reproductive system, however, the specific role of CTSB in regulating spermatogenesis and sperm maturation remained elusive. Hence, we generated Ctsb-/-mice using CRISPR/Cas9 technology. In Ctsb-/-mice, sperm count was significantly decreased while the level of morphologically abnormal sperm was markedly increased. Additionally, these mice had significantly lower levels of progressive motility sperm and elevated levels of immobilized sperm. Histological analysis showed slight vacuolization in the testis epithelium, as well as the loss of epididymal epithelium cells. Further investigation showed that autophagic activity was inhibited and apoptotic activity was increased in both the testis and epididymis of Ctsb-/-mice. Together, our findings demonstrate that CTSB plays an important role in spermatogenesis and sperm maturation in mice.

Automated summary

This study revealed the important role of CTSB in spermatogenesis and sperm maturation in mice. By generating Ctsb-/- mice using CRISPR/Cas9 technology, the researchers found that these mice had decreased sperm count, increased levels of morphologically abnormal sperm, decreased levels of progressively motile sperm, and increased levels of immotile sperm. Histological analysis showed vacuolization in the testis epithelium and loss of epididymal epithelium cells in Ctsb-/- mice. Furthermore, autophagic activity was inhibited and apoptotic activity was increased in both the testis and epididymis of Ctsb-/- mice.