Study on the effect and mechanism of curcumin in alleviating testicular injury induced by heat stress in mice

Heat stress(HS) has been shown to cause apoptosis and necrosis in the spermatogenic cells within the testicular tubules of male animals, leading to compromised sperm quality and reduced reproductive capability, potentially culminating in male infertility. Curcumin is known for its pharmacological properties, including antioxidative, anti-inflammatory, and immunoregulatory effects. The goal of study was to investigate the potential protective role of curcumin in safeguarding mouse testicular germ cells from heat-induced stress, aiming to maintain normal spermatogenesis and uncover the associated protective mechanisms. In this study, we have utilized a variety of techniques such as ELISA, immunohistochemistry, immunofluorescence, Western blot, and RT-qPCR to assess how effectively curcumin can mitigate heat-induced testicular damage in mice. The results indicated that curcumin significantly improved testicular function by reducing oxidative stress and apoptosis. Compared to the Heat Stress (HS), the sperm vitality of Curcumin + Heat Stress (CUR+HS) group increased by 30% (p<0.05). On this basi s, using the mouse spermatocyte line (GC2 cells) as a model, RNA-seq sequencing revealed that heat stress upregulates the expression of activated transcription factor 3 (Atf3), while curcumin can inhibit its expression. The study further explored the effects of overexpression and RNA interference of Atf3 in GC2 cell lines. The findings demonstrated that overexpression of Atf3 aggravated damage in GC2 cells, while inhibiting Atf3 activity markedly decreased apoptosis under heat stress conditions. Atf3 wa s found to enhance the transcription of Hsp70 and Egr1, suppress Bcl-2 expression. Curcumin reduced the binding of Atf3 to the Bcl-2 promoter, thereby upregulating Bcl-2 expression and alleviating spermatocyte damage caused by heat stress. Overall, the findings suggest a novel approach and perspective for addressing male reproductive system damage induced by heat stress.