Pei Xingyao, Liu Dingkuo, Li Jianjun, Li Liuan, Ding Xiangbin, Zhang Wenjuan, Li Zibin, Xu Gang, Li Cun, Li Daowen
Tianjin Key Laboratory of Agricultural Animal Breeding and Healthy Husbandry, College of Animal Science and Veterinary Medicine, Tianjin Agricultural University, Jinjing Road No.22, Xiqing District, Tianjin 300392, China; Department of Pharmacology and Toxicology, College of Veterinary Medicine, China Agricultural University, Yuanmingyuan West Road No.2, Haidian District, Beijing 100193, China.
Tianjin Key Laboratory of Agricultural Animal Breeding and Healthy Husbandry, College of Animal Science and Veterinary Medicine, Tianjin Agricultural University, Jinjing Road No.22, Xiqing District, Tianjin 300392, China; Tianjin Key Laboratory of Biological Feed Additive Enterprise, S&E Burgeoning Biotechnology (Tianjin) Co., Ltd, Tianjin 300383, China.
Sci Total Environ. 2023 Mar 20;865:161242. doi: 10.1016/j.scitotenv.2022.161242. Epub 2022 Dec 29.
Zinc oxide nanoparticles (ZnO NPs) have drawn serious concerns about their biotoxicity due to their extensive applications in biological medicine, clinical therapeutic, daily chemical production, food and agricultural additives. In our present study, we clarified hepatotoxic mechanism of ZnO NPs through investigating the crosstalk between autophagy and pyroptosis, a remaining enigma in hepatocyte stimulated by ZnO NPs. Based on the effects of autophagy intervention by Rapamycin (Rap) and 3-Methyladenine (3-MA), and the observation of pyroptosis morphology and related indexes, the autophagy and pyroptosis simultaneously initiated by ZnO NPs were interrelated and the autophagy characterized by autophagosome production and increased expression of autophagy proteins was identified as a protective response of ZnO NPs against pyroptosis. According to the analysis of protein expression and fluorescence localization, the NLRP3 inflammasome assemble and the classical Caspase-1/GSDMD-dependent pyroptosis induced by ZnO NPs was modulated by autophagy. In this process, the adjustment of TFEB expression and nuclear translocation by gene knockout and gene overexpression, further altered the tendency of ZnO NPs-induced pyroptosis via the regulation of autophagy and lysosomal biogenesis. The knockout of TFEB gene exacerbated the pyroptosis via autophagy elimination and lysosome inhibition. While the alleviation of NLRP3 generation and pyroptosis activation was observed after treatment of TFEB gene overexpression. Additionally, the siRNA interference confirmed that TRAF-6 was involved in the TFEB-mediated global regulation of autophagy-lysosome-pyroptosis in response to ZnO NPs. Accordingly, pyroptosis induced by ZnO NPs in hepatocyte could be significantly avoided by TFEB-regulated autophagy and lysosome, further providing new insights for the risk assessment and therapeutic strategy.
由于氧化锌纳米颗粒（ZnO NPs）在生物医药、临床治疗、日化生产、食品和农业添加剂等领域的广泛应用，其生物毒性已引起人们的严重关注。在我们目前的研究中，我们通过研究自噬与细胞焦亡之间的相互作用，阐明了ZnO NPs的肝毒性机制，这是ZnO NPs刺激肝细胞后仍未解开的谜团。基于雷帕霉素（Rap）和3-甲基腺嘌呤（3-MA）对自噬的干预作用，以及对细胞焦亡形态和相关指标的观察，发现ZnO NPs同时引发的自噬和细胞焦亡是相互关联的，以自噬体产生和自噬蛋白表达增加为特征的自噬被确定为ZnO NPs对细胞焦亡的一种保护反应。根据蛋白质表达和荧光定位分析，自噬调节了ZnO NPs诱导的NLRP3炎性小体组装和经典的半胱天冬酶-1/ Gasdermin D依赖性细胞焦亡。在此过程中，通过基因敲除和基因过表达对转录因子EB（TFEB）表达和核转位的调节，进一步通过自噬和溶酶体生物合成的调控改变了ZnO NPs诱导细胞焦亡的趋势。TFEB基因敲除通过消除自噬和抑制溶酶体而加剧细胞焦亡。而TFEB基因过表达处理后，NLRP3生成和细胞焦亡激活得到缓解。此外，小干扰RNA（siRNA）干扰证实，肿瘤坏死因子受体相关因子6（TRAF-6）参与了TFEB介导的对ZnO NPs的自噬-溶酶体-细胞焦亡的整体调控。因此，TFEB调节的自噬和溶酶体可以显著避免ZnO NPs在肝细胞中诱导的细胞焦亡，这进一步为风险评估和治疗策略提供了新的见解。
