Exploration and verification of the mechanism of PARP1/SIRT6/poly(ADP-ribosyl)ation in regulating zearalenone-induced injury in bovine sertoli cells

Zearalenone (ZEA) is a prevalent mycotoxin in feed, known for its potent reproductive toxicity that poses a significant threat to male reproductive function. Sertoli cells (SCs) are essential for spermatogenesis. Although ZEA induces oxidative damage to SCs, the underlying mechanisms and effective prevention and control strategies remain underexplored. We found that ZEA treatment induced oxidative stress, increased γH2AX and tail moment, damaged cellular DNA, and consequently suppresses cell activity and function. Furthermore, exposure to ZEA diminishes the levels of DNA repair and antioxidant pathway proteins, thereby compromising both antioxidant capacity and DNA repair capabilities. PARP1 is the first key repair protein to identify DNA damage, and its catalytic poly(ADP-ribosyl)ation is a signal to recruit repair proteins. ZEA exposure increased PARP1, but reduced poly(ADP-ribosyl)ation and its downstream repair proteins, as well as antioxidant pathway proteins. This indicates that ZEA damages DNA and suppresses both DNA repair capacity and antioxidant defense capabilities. Inhibiting PARP1 further reduces DNA damage repair and antioxidant protein levels, thereby exacerbating DNA damage. NAD+ is the only substrate for PARP1 enzymatic reaction. NAD+ treatment increases the levels of DNA repair proteins and antioxidant proteins, and alleviates DNA damage caused by ZEA exposure. Furthermore, overexpression of sirt6 increased poly(ADP-ribosyl)ation and mitigated DNA damage, exerting a positive regulatory effect on alleviating ZEA toxicity. In summary, these findings underscore the regulatory function of PARP1 and its mediated poly(ADP-ribosyl)ation in ZEA-induced DNA damage in bovine SCs, offering new insights for mitigating ZEA-induced male reproductive dysfunction.