Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, China.
School of Basic Medical Science, Guizhou Medical University, Guiyang 550002, China.
Biomed Res Int. 2022 Aug 21;2022:7380324. doi: 10.1155/2022/7380324. eCollection 2022.
To explore the function and mechanism of Sirt-1 in fluorine-induced liver injury.
Fluorosis rats were first established. The fluorine content, pathological structure, collagen fibers, and fibrosis in liver tissues were tested through the fluoride ion selective electrode method, H&E, Masson, and Sirius red staining; alanine aminotransferase (ALT), aspartate aminotransferase (AST), interleukin 18 (IL-18), and tumor necrosis factor- (TNF-) levels in rat serum were also analyzed using ELISA kits. Then, the fluorosis cell model was built, which was also alleviated with NaF, Sirt-1 siRNAs, or endoplasmic reticulum stress (ERS) alleviator (4-PBA). CCK-8 also assessed cell proliferation; RT-qPCR or Western blots detect sirtuin-1 (Sirt-1), protein kinase R- (PKR-) like endoplasmic reticulum kinase (PERK), and endoplasmic reticulum stress (ERS) and apoptosis-related protein levels in liver tissue.
Our results uncovered that fluorine exposure could aggravate the pathological damage and fibrosis of rat liver tissues and increase indicators related to liver injury. And fluoride exposure also could downregulate Sirt-1 and upregulate ERS-related proteins (PERK, 78-kD glucose-regulated protein (GRP-78), and activating transcription factor 6 (ATF6)) and apoptosis-related protein (caspase-3 and C/EBP-homologous protein (CHOP)) in rat liver tissues. Besides, we proved that fluoride exposure could suppress proliferation and enhances ERS and apoptotic pathways in AML12 cells by downregulating Sirt-1. Moreover, we revealed that ERS alleviator (4-PBA) could induce proliferation and prevent ERS and apoptosis in fluorine-exposed AML12 cells.
We suggested that fluorine exposure can induce hepatocyte ERS and apoptosis through downregulation of Sirt-1.
探讨 Sirt-1 在氟诱导肝损伤中的作用及机制。
首先建立氟中毒大鼠模型，采用氟离子选择电极法、H&E、Masson、天狼猩红染色检测大鼠肝组织中氟含量、病理结构、胶原纤维及纤维化程度，酶联免疫吸附试验检测大鼠血清中天冬氨酸氨基转移酶（ALT）、丙氨酸氨基转移酶（AST）、白细胞介素 18（IL-18）、肿瘤坏死因子-（TNF-）水平；构建氟中毒细胞模型，用 NaF、Sirt-1 siRNAs、内质网应激（ERS）缓解剂 4-PBA 进行缓解，CCK-8 检测细胞增殖，RT-qPCR 或 Western blot 检测肝组织中 Sirtuin-1（Sirt-1）、蛋白激酶 R-（PKR-）样内质网激酶（PERK）、内质网应激（ERS）和凋亡相关蛋白水平。
氟暴露可加重大鼠肝组织的病理损伤和纤维化，增加与肝损伤相关的指标；氟暴露还可下调 Sirt-1，上调内质网应激相关蛋白（PERK、78-kD 葡萄糖调节蛋白（GRP-78）、激活转录因子 6（ATF6））和凋亡相关蛋白（caspase-3、C/EBP 同源蛋白（CHOP））；此外，我们证实氟暴露通过下调 Sirt-1 抑制 AML12 细胞增殖，增强内质网应激和凋亡途径；此外，我们发现内质网应激缓解剂（4-PBA）可诱导增殖并防止氟暴露的 AML12 细胞发生内质网应激和凋亡。
我们认为氟暴露可通过下调 Sirt-1 诱导肝细胞内质网应激和凋亡。
