Microcystin-leucine-arginine induces apical ectoplasmic specialization disassembly. (February 2021)

• Record Type: Journal Article
• Authors: Xu, Dihui; Wang, Jing; Ma, Yuhan; Ding, Jie; Han, Xiaodong; Chen, Yabing
• Is Part Of: Chemosphere. Volume 264(2021)Part 1
• Publication Date: 2021-02
• Subjects: Microcystin-leucine-arginine -- Spermatid exfoliation -- The apical ectoplasmic specialization -- Palladin -- Autophagy; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.128440
• Languages: English
• ISSNs: 0045-6535

Abstract

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. Graphical abstract: Image 1 Highlights: Chronic oral exposure to MC-LR induced spermatid exfoliation in mice. MC-LR disrupted the organization of F-actin in Sertoli cells. MC-LR led to the disorder of the apical ectoplasmic specialization. MC-LR promoted the degradation of Palladin via AMPK/ULK1-mediated autophagy pathway in Sertoli cells.