TRPM7 exacerbates testicular ischemia-reperfusion injury by activating the NLRP3 inflammasome to drive pyroptosis.

BACKGROUND

Testicular ischemia-reperfusion injury (IRI) represents a critical determinant of fertility outcomes following torsion. Pyroptosis, an inflammatory form of cell death, involved in IRI within other organs, but its role and regulation in testicular damage remain unclear. The cation channel-kinase TRPM7 is a known stress sensor, yet its role in testicular IRI is unknown.

METHODS

Both a murine testicular I/R model and an in vitro OGD/R model using GC-1 cells were constructed. The extent of pyroptosis was determined by detecting cleaved caspase-1 (CASP1), GSDMD-N, and IL-1β/18. TRPM7 expression was estimated by qRT-PCR, western blot (WB), and immunohistochemistry. Gain- and loss-of-function investigations were conducted using overexpression plasmids, siRNA, and the inhibitor NS8593. The involvement of the NLRP3 inflammasome was tested using its inhibitor MCC950.

RESULTS

Testicular I/R and OGD/R robustly activated pyroptosis. TRPM7 expression was significantly upregulated in both models. Functionally, TRPM7 overexpression exacerbated OGD/R-induced cell death and pyroptosis, while its knockdown or inhibition attenuated these effects. Mechanistically, TRPM7 triggered the expression and stimulation of the NLRP3 inflammasome. Critically, the NLRP3 inhibitor MCC950 completely reversed the enhanced pyroptosis driven by TRPM7 overexpression.

CONCLUSION

This study identifies a novel TRPM7/NLRP3/pyroptosis axis as a key pathogenic mechanism in testicular IRI. TRPM7 acts as an upstream regulator, transducing ischemic stress into NLRP3 inflammasome stimulation and inflammatory cell death, positioning it as a prospective therapeutic target.