Ti3C2 nanosheet-induced autophagy derails ovarian functions.

BACKGROUND: Two-dimensional ultrathin Ti3C2 (MXene) nanosheets have gained significant attention in various biomedical applications. Although previous studies have described the accumulation and associated damage of Ti3C2 nanosheets in the testes and placenta. However, it is currently unclear whether Ti3C2 nanosheets can be translocated to the ovaries and cause ovarian damage, thereby impairing ovarian functions. RESULTS: We established a mouse model with different doses (1.25, 2.5, and 5 mg/kg bw/d) of Ti3C2 nanosheets injected intravenously for three days. We demonstrated that Ti3C2 nanosheets can enter the ovaries and were internalized by granulosa cells, leading to a decrease in the number of primary, secondary and antral follicles. Furthermore, the decrease in follicles is closely associated with higher levels of FSH and LH, as well as increased level of E2 and P4, and decreased level of T in mouse ovary. In further studies, we found that exposure toTi3C2 nanosheets increased the levels of Beclin1, ATG5, and the ratio of LC3II/Ι, leading to autophagy activation. Additionally, the level of P62 increased, resulting in autophagic flux blockade. Ti3C2 nanosheets can activate autophagy through the PI3K/AKT/mTOR signaling pathway, with oxidative stress playing an important role in this process. Therefore, we chose the ovarian granulosa cell line (KGN cells) for in vitro validation of the impact of autophagy on the hormone secretion capability. The inhibition of autophagy initiation by 3-Methyladenine (3-MA) promoted smooth autophagic flow, thereby partially reduced the secretion of estradiol and progesterone by KGN cells; Whereas blocking autophagic flux by Rapamycin (RAPA) further exacerbated the secretion of estradiol and progesterone in cells. CONCLUSION: Ti3C2 nanosheet-induced increased secretion of hormones in the ovary is mediated through the activation of autophagy and impairment of autophagic flux, which disrupts normal follicular development. These results imply that autophagy dysfunction may be one of the underlying mechanisms of Ti3C2-induced damage to ovarian granulosa cells. Our findings further reveal the mechanism of female reproductive toxicity induced by Ti3C2 nanosheets.

Inhibition of USP14 Suppresses ROS-dependent Ferroptosis and Alleviates Renal Ischemia/Reperfusion Injury.

The ubiquitin-specific protease 14 (USP14) is a deubiquitinating enzyme, its inhibitor was reported could alleviate the ischemia/reperfusion (I/R)-stimulated cerebral neuronal damage. However, its specific role in I/R-induced acute kidney injury (AKI) remains unclear. We established hypoxia/reoxygenation (H/R)-induced HK-2 cell injury model in vitro and I/R-induced kidney injury mice model in vivo. The expression or activity of USP14 was inhibited by siRNA or IU1, a small molecule inhibitor of USP14. ROS were scavenged by N-acetyl-cysteine (NAC). Biochemical index analysis and hematoxylin & eosin (H&E) staining were performed to evaluate renal injury. The results indicated that USP14 was upregulated in H/R-induced HK-2 cells and kidney tissues of I/R mice. Inhibition of USP14 suppressed the cell death, inflammatory, oxidative stress and reactive oxygen species (ROS)-dependent ferroptosis of H/R-induced HK-2 cells. What's more, IU1 and NAC effectively alleviated renal injury of I/R mice. In summary, this study suggested that inhibition of USP14 protected renal from I/R injury.