Leptin attenuates heat stress-induced mitoxyperilysis in porcine Sertoli cells by suppressing the mtDNA-cGAS-STING axis

BACKGROUND: Mammalian spermatogenesis is highly temperature-sensitive and relies critically on the protective function of Sertoli cells. Although heat stress is known to affect Sertoli cell fate, it remains unclear whether it triggers mitoxyperilysis and by what mechanism. Leptin is a multifunctional hormone that regulates energy metabolism and is critical for mitochondrial integrity across various cell types. However, whether leptin safeguards Sertoli cells from heat stress‑induced mitoxyperilysis remains unclear. RESULTS: In this study, the results demonstrated that heat stress induced mitochondrial oxidative damage, leading to mitochondrial DNA (mtDNA) leakage and metabolic reprogramming. Mechanistically, heat stress compromised mitochondrial membrane integrity by promoting aberrant mPTP opening, triggering BAX/BAK oligomerization, and facilitating VDAC1 oligomerization, collectively leading to mtDNA leakage into the cytosol. The cytosolic mtDNA activated the cGAS-STING signaling, subsequently triggering TBK1-IRF3 and NF-κB signaling cascades, which drove inflammatory cytokine production and ultimately culminated in mitoxyperilysis. Importantly, leptin safeguarded mitochondrial integrity, effectively prevented mtDNA release and suppressed cGAS-STING activation, thereby attenuating mitoxyperilysis. CONCLUSIONS: Collectively, these findings suggest that leptin may serve as a critical guardian of mitochondrial integrity that protects Sertoli cells from heat stress-induced mitoxyperilysis, highlighting its potential to support future therapeutic strategies for heat stress-related male reproductive dysfunction.