School of Water and Environment, Chang'an University, Xi'an, 710054, China; Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an, 710054, China.
School of Water and Environment, Chang'an University, Xi'an, 710054, China; Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an, 710054, China.
Chemosphere. 2020 Mar;243:125437. doi: 10.1016/j.chemosphere.2019.125437. Epub 2019 Nov 21.
Hexavalent chromium is one of the major detrimental heavy metal pollutants. B. gargarizans tadpoles were treated with different concentrations of Cr (0, 13, 52, 104, 208, and 416 μg Cr L) from Gs 2 to Gs 42. The effect of Cr on histopathological alterations and transcript levels of fatty acid metabolism-related genes as well as fatty acids composition and content in liver were examined. Histopathological changes were observed in liver at 52, 104, 208, and 416 μg Cr L. Moreover, RT-qPCR analyses showed the downregulated mRNA levels of the genes related to fatty acid synthesis (SCD, MECR, TECR and ELOVL1) and fatty acid β-oxidation (ACOT1, PPT1, HADH and ACAA2) at 416 μg Cr L. However, the mRNA expression of fatty acid β-oxidation-related genes (ECHS1, HADHA and ACAA1) were significantly upregulated at 13, 52, 104, 208 and 416 μg Cr L. In situ hybridization revealed BSEP was expressed in hepatocyte nucleus and plasma membrane, and HSD17B12 was abundantly expressed in the plasma membrane. The HSD17B12 mRNA levels were significantly upregulated in tadpoles exposed to all Cr treatment groups, while the BSEP mRNA levels were downregulated at 104, 208 and 416 μg Cr L groups compared to control. In addition, an increase in polyunsaturated fatty acids and a decrease in monounsaturated fatty acids were found in 52, 104 and 416 μg Cr L groups. Overall, chronic exposure to Cr may suppress fatty acid synthesis, disturb fatty acid β-oxidation, aggravate disorders of hepatic function and induce hepatic impairment in B. gargarizans tadpoles.
六价铬是主要的有害重金属污染物之一。从 Gs2 到 Gs42，用不同浓度的 Cr（0、13、52、104、208 和 416μg Cr L）处理棘胸蛙蝌蚪。研究了 Cr 对肝组织病理学改变和脂肪酸代谢相关基因转录水平以及肝组织中脂肪酸组成和含量的影响。在 52、104、208 和 416μg Cr L 时观察到肝组织的组织病理学变化。此外，RT-qPCR 分析显示，在 416μg Cr L 时，与脂肪酸合成（SCD、MECR、TECR 和 ELOVL1）和脂肪酸β-氧化（ACOT1、PPT1、HADH 和 ACAA2）相关的基因的 mRNA 水平下调。然而，在 13、52、104、208 和 416μg Cr L 时，脂肪酸β-氧化相关基因（ECHS1、HADHA 和 ACAA1）的 mRNA 表达显著上调。原位杂交显示 BSEP 在肝细胞核和质膜中表达，HSD17B12 在质膜中大量表达。在所有 Cr 处理组中，HSD17B12 mRNA 水平显著上调，而在 104、208 和 416μg Cr L 组中，BSEP mRNA 水平与对照组相比下调。此外，在 52、104 和 416μg Cr L 组中发现多不饱和脂肪酸增加，单不饱和脂肪酸减少。总的来说，慢性 Cr 暴露可能会抑制脂肪酸合成，扰乱脂肪酸β-氧化，加重肝功能紊乱，并在棘胸蛙蝌蚪中诱导肝损伤。
