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  2. Microcystin-LR inhibits testosterone synthesis via reactive oxygen species-mediated GCN2/eIF2α pathway in mouse testes

Microcystin-LR inhibits testosterone synthesis via reactive oxygen species-mediated GCN2/eIF2α pathway in mouse testes

  • Sci Total Environ. 2021 Aug 10:781:146730. doi: 10.1016/j.scitotenv.2021.146730.
Lan Gao 1 Jing Chen 2 Jian Li 2 An-Qi Cui 2 Wei-Wei Zhang 2 Xiu-Liang Li 2 Jing Wang 2 Xiao-Yi Zhang 2 Ye Zhao 3 Yuan-Hua Chen 2 Cheng Zhang 2 Hua Wang 4 De-Xiang Xu 5
Affiliations

Affiliations

  • 1 Department of Toxicology & Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes, Anhui Medical University, Hefei 230032, China. Electronic address: [email protected].
  • 2 Department of Toxicology & Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes, Anhui Medical University, Hefei 230032, China.
  • 3 Department of Nuclear Medicine, Anhui Medical University, Hefei 230032, China.
  • 4 Department of Toxicology & Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes, Anhui Medical University, Hefei 230032, China. Electronic address: [email protected].
  • 5 Department of Toxicology & Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes, Anhui Medical University, Hefei 230032, China. Electronic address: [email protected].
Abstract

Previous studies demonstrated that microcystin-leucine-arginine (MC-LR) disrupted testosterone (T) synthesis, but the underlying mechanisms are not entirely elucidated. This study aims to explore the role of Reactive Oxygen Species (ROS)-mediated GCN2/eIF2α activation on MC-LR-induced disruption of testicular T synthesis. Male mice were intraperitoneally injected with MC-LR (0 or 20 μg/kg) daily for 5 weeks. Serum T was decreased in MC-LR-exposed mice (0.626 ± 0.122 vs 24.565 ± 8.486 ng/ml, P < 0.01), so did testicular T (0.667 ± 0.15 vs 8.317 ± 1.387 ng/mg protein, P < 0.01). Steroidogenic proteins including StAR, CYP11A1 and CYP17A1 were downregulated in MC-LR-exposed mouse testes and TM3 cells. Mechanistically, p-GCN2 and p-eIF2α were elevated in MC-LR-exposed TM3 cells. GCN2iB attenuated MC-LR-induced GCN2 and eIF2α phosphorylation in TM3 cells. Moreover, GCN2iB attenuated MC-LR-induced downregulation of steroidogenic proteins in TM3 cells. Further analysis found that cellular ROS were elevated and HO-1 was upregulated in MC-LR-exposed TM3 cells. PBN rescued MC-LR-induced activation of GCN2/eIF2α signaling in TM3 cells. Additionally, pretreatment with PBN attenuated MC-LR induced downregulation of steroidogenic proteins and synthases in TM3 cells. These results suggest that ROS-mediated GCN2/eIF2α activation contributes partially to MC-LR-caused downregulation of steroidogenic proteins and synthases. The present study provides a new clue for understanding the mechanism of MC-LR-induced endocrine disruption.

Keywords

GCN2/eIF2α signaling; Leydig cell; MC-LR; Reactive oxygen species; Testosterone synthesis.

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