Microcystin-leucine-arginine induces apical ectoplasmic specialization disassembly

  • Chemosphere. 2021 Feb;264(Pt 1):128440. doi: 10.1016/j.chemosphere.2020.128440.
Dihui Xu  1 Jing Wang  2 Yuhan Ma  3 Jie Ding  4 Xiaodong Han  5 Yabing Chen  6
Affiliations
  • 1. Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, China. Electronic address: [email protected].
  • 2. Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, China. Electronic address: [email protected].
  • 3. Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, China. Electronic address: [email protected].
  • 4. Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, China. Electronic address: [email protected].
  • 5. Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, China. Electronic address: [email protected].
  • 6. Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, China. Electronic address: [email protected].
Abstract

Microcystin-leucine-arginine (MC-LR) has been identified to be a hazardous material to cause hepatotoxicity. In this study, mice were exposed to MC-LR dissolved in drinking water at doses of 1, 10, 20 and 30 μg/L for 90 and 180 days, respectively. We validated MC-LR accelerated spermatid exfoliation and caused large vacuoles in testes, reducing sperm count and increasing percentage of morphologically abnormal sperm. Furthermore, we found MC-LR induced the apical ectoplasmic specialization (ES) disassembly by disrupting F-actin organization. Further studies identified that downregulation of Palladin, the actin crosslinking protein, might be associated with disassembly of the apical ES in mice testis following MC-LR exposure. We also confirmed that MC-LR disrupted the interaction between Palladin and Other actin-related proteins and thus impeded the F-actin organization. Additionally, we found that Autophagy initiated by AMPK/ULK1 signaling pathway mediated the degradation of Palladin in Sertoli cells challenged with MC-LR. Following exposure to MC-LR, reduced PP2A activity and upregulated expression of LKB1 and CAMKK2 could activate AMPK. In conclusion, these results revealed MC-LR induced the degradation of Palladin via AMPK/ULK1-mediated Autophagy, which might result in the apical ES disorder and spermatid exfoliation from spermatogenic epithelium. Our work may provide a new perspective to understand MC-LR-induced male infertility.

Keywords
Autophagy; Microcystin-leucine-arginine; Palladin; Spermatid exfoliation; The apical ectoplasmic specialization.
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