Distinctive molecular features of regenerative stem cells in the damaged male germline

Area of Science:

• Reproductive biology
• Stem cell biology
• Cancer research

Background:

• Male fertility is maintained by spermatogonial stem cells (SSCs) responsible for sperm production.
• Chemotherapy can cause infertility by damaging germline cells, including SSCs.
• Understanding SSC regenerative pathways is vital for restoring fertility after cancer treatment.

Purpose of the Study:

• To identify molecular features of regenerative SSCs after chemotherapy-induced damage.
• To characterize changes in the undifferentiated spermatogonial pool during germline recovery.
• To elucidate the role of growth factor signaling pathways in SSC regeneration.

Main Methods:

• Single-cell analysis of spermatogonial stem cells in models of chemotherapy-induced germline damage and recovery.
• Investigation of PI3K/AKT and mTORC1 signaling pathways.
• Assessment of the transcription factor FOXM1's role in regeneration.

Main Results:

• Regenerative SSCs exhibit increased mitotic activity and altered growth factor signaling.
• Transient activation of mTORC1 is critical for SSC regeneration, while sustained signaling is detrimental.
• Inhibition of growth factor signaling impairs SSC regenerative features and limits germline recovery.
• FOXM1 is identified as a target of growth factor signaling involved in SSC regeneration.

Conclusions:

• SSCs undergo dynamic functional changes post-chemotherapy to facilitate germline recovery.
• Microenvironmental growth factors play a critical role in promoting a regenerative state in SSCs.
• Targeting specific growth factor pathways may offer strategies to preserve or restore male fertility.