C/EBP-β/MeCP2/Wnt Axis Participates in the Testicular Injury in Rats Under Simulated Microgravity Conditions.

BACKGROUND AND

OBJECTIVE

As space exploration advances, the effects of the microgravity environment on testicular injury and spermatogenic function in astronauts have attracted widespread attention, but the underlying mechanisms remain unclear.

METHODS

In this study, testicular morphometry and Johnsen score were used to evaluate the degree of testicular injury. Then the upstream transcription factors of MeCP2 were verified using the dual-luciferase reporter assay. Finally, the expression of C/EBP-β, MeCP2, and Wnt4/β-Catenin protein was detected to clarify the regulatory pathway.

RESULTS

Under microgravity conditions, MeCP2 expression was significantly reduced in rat testes and was positively correlated with testicular morphometric indices. Subsequently, the dual-luciferase reporter assay revealed that C/EBP-β directly bound to the promoter sequence of MeCP2, initiating its transcriptional activity. Meanwhile, the expression of C/EBP-β, Wnt4, and β-Catenin was reduced in the testes under microgravity conditions.

CONCLUSIONS

In conclusion, our study proposed that C/EBP-β regulated MeCP2, consequently, inhibited the Wnt4/β-Catenin pathway activity, thereby participating in microgravity-induced testicular injury.