Department of Toxicology & Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes, School of Public Health, Anhui Medical University, Hefei 230032, China.
Department of Toxicology & Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes, School of Public Health, Anhui Medical University, Hefei 230032, China.
Environ Int. 2024 Mar;185:108488. doi: 10.1016/j.envint.2024.108488. Epub 2024 Feb 9.
Inorganic trivalent arsenic (iAs) at environmentally relevant levels has been found to cause developmental toxicity. Maternal exposure to iAs leads to enduring hepatic lipid deposition in later adult life. However, the exact mechanism in iAs induced hepatic developmental hazards is still unclear. In this study, we initially found that gestational exposure to iAs at an environmentally relevant concentration disturbs lipid metabolism and reduces levels of alpha-ketoglutaric acid (α-KG), an important mitochondrial metabolite during the citric acid cycle, in fetal livers. Further, gestational supplementation of α-KG alleviated hepatic lipid deposition caused by early-life exposure to iAs. This beneficial effect was particularly pronounced in female offspring. α-KG partially restored the β-oxidation process in hepatic tissues by hydroxymethylation modifications of carnitine palmitoyltransferase 1a (Cpt1a) gene during fetal development. Insufficient β-oxidation capacities probably play a crucial role in hepatic lipid deposition in adulthood following in utero arsenite exposure, which can be efficiently counterbalanced by replenishing α-KG. These results suggest that gestational administration of α-KG can ameliorate hepatic lipid deposition caused by iAs in female adult offspring partially through epigenetic reprogramming of the β-oxidation pathway. Furthermore, α-KG shows potential as an interventive target to mitigate the harmful effects of arsenic-induced hepatic developmental toxicity.
无机三价砷(iAs)在环境相关水平下已被发现会导致发育毒性。母体暴露于 iAs 会导致成年后肝脏脂质沉积持久存在。然而,iAs 诱导的肝发育危害的确切机制仍不清楚。在这项研究中,我们最初发现环境相关浓度的妊娠期 iAs 暴露会扰乱脂质代谢并降低柠檬酸循环中一种重要的线粒体代谢物α-酮戊二酸(α-KG)的水平。此外,妊娠期补充 α-KG 可减轻早期生命暴露于 iAs 引起的肝脂质沉积。这种有益的影响在雌性后代中尤为明显。α-KG 通过胎儿发育过程中肉碱棕榈酰转移酶 1a(Cpt1a)基因的羟甲基化修饰,部分恢复了肝组织中的β-氧化过程。在子宫内亚砷酸盐暴露后成年期肝脏脂质沉积中,β-氧化能力不足可能起着至关重要的作用,而通过补充 α-KG 可以有效地平衡这种作用。这些结果表明,妊娠期给予 α-KG 可部分通过β-氧化途径的表观遗传重编程来改善 iAs 引起的雌性成年后代的肝脂质沉积。此外,α-KG 可能作为一种干预靶点,减轻砷诱导的肝发育毒性的有害影响。