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.

HADH suppresses clear cell renal cell carcinoma progression through reduced NRF2-dependent glutathione synthesis.

BACKGROUND: Clear cell renal cell carcinoma (ccRCC) is a serious threat to human life. It is very important to clarify the pathogenesis of ccRCC. In this study we evaluated the clinical value of HADH and explored its role and mechanism in the malignant progression of ccRCC. METHODS: HADH expression and its relationship with prognosis were analyzed using bioinformatics database. RT-PCR, Western blot and immunohistochemistry were used to examine the expression of HADH in ccRCC tissues and tissue microarrays. To examine the cell proliferation, apoptosis, migration and invasion ability, ccRCC cells with HADH overexpressed were constructed. Xenograft experiments were performed to determine the role of HADH. Non-target metabolomics was applied to explore the potential metabolic pathway by which HADH inhibited ccRCC progression. Plasmid pcDNA3.1-NRF2 was used to confirm whether HADH inhibited the process of ccRCC cells through NRF2-related glutathione (GSH) synthesis. RESULTS: Bioinformatics database analysis showed that HADH expression was significantly decreased in ccRCC tissues, and its low expression predicted a poor prognosis. Both ccRCC tissues and tissue microarrays exhibited a significantly decreased HADH level compared with adjacent normal renal tissues. HADH overexpression inhibited the malignant behaviors of ccRCC cells. Furthermore, HADH overexpression attenuated GSH synthesis and induced oxidative stress damage. Exogenously increased NRF2 effectively attenuated the inhibitive effect of HADH overexpression on ccRCC cells. CONCLUSION: Our data revealed that HADH suppressed the malignant behaviors of ccRCC cells by attenuating GSH synthesis through inhibition of NRF2 nuclear translocation, and HADH might be a novel therapeutic target for ccRCC treatment.

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.