Sex-specific effects of fluoride and lead on thyroid endocrine function in zebrafish (Danio rerio). (1st November 2022)

• Record Type: Journal Article
• Authors: Lu, Yuting; Zhang, Xiulin; Chen, Jianjie; Cao, Jinling; Feng, Cuiping; Yun, Shaojun; Cheng, Yanfeng; Cheng, Feier
• Is Part Of: Chemico-biological interactions. Volume 367(2022)
• Publication Date: 2022-11-01
• Subjects: Fluoride -- Lead -- Zebrafish (Danio rerio) -- Thyroid -- Endocrine-related genes -- Sex-specific effect; Biochemistry -- Periodicals; Toxicological chemistry -- Periodicals; Biochemistry -- Periodicals; Biologie moléculaire -- Périodiques; Biochimie -- Périodiques; Toxicologie biochimique -- Périodiques; 572
• DOI: 10.1016/j.cbi.2022.110151
• Languages: English
• ISSNs: 0009-2797

Abstract

Abstract: Fluoride (F) and lead (Pb) are widespread pollutants in the environment. F and Pb affect the thyroid endocrine system, but the mechanism of action between F and Pb is still unclear. In this study, in order to evaluate the effects of F or/and Pb on histopathological changes, antioxidant indices, the levels of thyroid hormones (THs), and the expression of endocrine-related genes in zebrafish thyroid. One thousand and two hundred zebrafish (female:male = 1:1) were randomly divided into four groups: control group (C group), 80 mg/L F group (F group), 60 mg/L Pb group (Pb group), and 80 mg/L F + 60 mg/L Pb group (F + Pb group) for 45 d and 90 d. Histopathological sections showed a loss of glia and follicular epithelial hyperplasia in the thyroid gland after exposure to F and Pb. Oxidative stress in the thyroid was induced after F and Pb exposure. And each oxidation index was increased after F + Pb exposure. Combined F and Pb exposure aggravated the downregulation of thyroid hormones T3 and T4 compared to exposure alone. Furthermore, F and Pb exposure altered the expression of thyroid endocrine-related genes in a time-dependent manner. These results indicate that F and Pb can affect the endocrine system of thyroid by changing the tissue structure, antioxidant capacity, thyroid hormone secretion and the levels of endocrine-related genes in thyroid. F and Pb can also produce toxic effects on thyroid, but the degree of poisoning is different in different indicators, mainly for the additive effect between them. Additionally, males are more sensitive than females to F or Pb toxicity. However, the specific molecular mechanism of the effects of F and Pb on thyroid endocrine system needs to be further studied. Highlights: F and Pb caused the damage of thyroid gland microstructure in zebrafish. F and Pb disturbed the oxidative stress balance and thyroid hormones in thyroid gland. F and Pb exposure altered the expression of thyroid endocrine-related genes. F and Pb had synergistic effects on thyroid gland damage in zebrafish. Males are more sensitive to F or Pb toxicity than females.