Grass carps co-exposed to environmentally relevant concentrations of cypermethrin and sulfamethoxazole bear immunodeficiency and are vulnerable to subsequent Aeromonas hydrophila infection. (November 2020)

• Record Type: Journal Article
• Authors: Zhao, Hongjing; Wang, Yu; Guo, Menghao; Mu, Mengyao; Yu, Hongxian; Xing, Mingwei
• Is Part Of: Environmental pollution. Volume 266:Part 3(2020)
• Publication Date: 2020-11
• Subjects: Cypermethrin or/and sulfamethoxazole -- Host resistance challenge -- Immunotoxicity -- Grass carp -- Spleen; CMN cypermethrin -- SMZ sulfamethoxazole -- C3 Complement 3 -- CRP C-reactive protein -- LYS lysozyme -- ROS reactive oxygen species -- TLRs Toll-like receptors -- PAMPs pathogen-associated molecular patterns -- SOD superoxide dismutase -- CAT catalase -- MDA malondialdehyde -- GSH glutathione -- ELISA Enzyme-linked immunosorbent assay -- MMC melanomacrophage centers -- A. hydrophila Aeromonas hydrophil; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.115156
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The aquatic ecosystem is seriously damaged because of the heavy use of pesticides and antibiotics. Fish is the indispensable link between environmental pollution and human health. However, the toxic effects of environment-related concentrations of pesticides and antibiotics in fish have not been thoroughly studied. In this study, grass carps exposed to cypermethrin (CMN, 0.651 μg/L) or/and sulfamethoxazole (SMZ, 0.3 μg/L) for 42 days caused oxidative stress, apoptosis and immunodeficiency in the spleen of grass carps. CMN or/and SMZ exposure led to oxidative damage (consumption of antioxidant enzymes (superoxide dismutase and catalase)) and lipid peroxidation (accumulation of malondialdehyde), induced apoptosis (increases in TUNEL index, Bax/bcl-2, p53, puma and Caspase family expression). In addition, the levels of immunoglobulin M (IgM), complement 3 (C3) were significantly decreased in all treatment groups, which trend was also found in C-reactive protein in CMN and MIX group, and lysozyme in MIX group. Transcription of almost all genes involved in the Toll-like receptors (TLR) signaling pathway was up-regulated under CMN or/and SMZ exposure. However, when subsequently attacked by Aeromonas hydrophila for 2 days, the TLR pathway was inhibited in spleens of all treatment groups accompanied by higher mortality. Overall, the environmentally relevant concentration of CMN and SMZ damages the immune system, triggering oxidative stress and apoptosis in carps. And by affecting the conduction of TLR signaling pathway, CMN or/and SMZ exposure inhibits the innate immune response of fish and reducing their disease resistance. This study highlights the importance of rational and regulated use of these pesticides and antibiotics. Graphical abstract: Image 1 Highlights: CMN and SMZ induced immunotoxicity in carp at environmentally relevant concentrations. Disturbs in TLR-MyD88 signaling pathway was induced by CMN or/and SMZ. CMN and SMZ exposure rendered fish vulnerable to A. hydrophila infection.