Differential modulation of oxidative stress, antioxidant defense, histomorphology, ion-regulation and growth marker gene expression in goldfish (Carassius auratus) following exposure to different dose of virgin microplastics

• Published in: Comparative biochemistry and physiology. Toxicology & pharmacology 2020-12, Vol.238, p.108862, Article 108862
• Main Authors: Romano, Nicholas, Renukdas, Nilima, Fischer, Hayden, Shrivastava, Jyotsna, Baruah, Kartik, Egnew, Nathan, Sinha, Amit Kumar
• Format: Article
• Language: English
• Subjects: Animals; Antioxidant defense system; Antioxidants - metabolism; Brain - drug effects; Brain - metabolism; Brain - pathology; Dose-Response Relationship, Drug; Environmental Sciences; Gene Expression - drug effects; GH/IGF-1 axis; Gills - drug effects; Gills - metabolism; Gills - pathology; Goldfish - anatomy & histology; Goldfish - genetics; Goldfish - growth & development; Goldfish - metabolism; Hemorrhaging; Insulin-Like Growth Factor Binding Protein 1 - genetics; Insulin-Like Growth Factor Binding Protein 1 - metabolism; Liver - drug effects; Liver - metabolism; Liver - pathology; Microplastics; Microplastics - toxicity; Miljövetenskap; Oxidative stress; Oxidative Stress - drug effects; Proton-Translocating ATPases - genetics; Proton-Translocating ATPases - metabolism; Receptors, Somatotropin - genetics; Receptors, Somatotropin - metabolism; Sodium-Potassium-Exchanging ATPase - genetics; Sodium-Potassium-Exchanging ATPase - metabolism; Water Pollutants, Chemical - toxicity
• ISSN: 1532-0456; 1878-1659
• DOI: 10.1016/j.cbpc.2020.108862

Goldfish (Carassius auratus) juveniles were exposed to virgin polyvinyl chloride microplastics (PVC-MPs) in triplicate at 0, 0.1 or 0.5 mg/L for four days. Afterwards, the histopathology of the gills, liver and intestines were examined, along with various antioxidant enzymes and indicators of oxidative damage (malondialdehyde (MDA) and hydrogen peroxide (H2O2)), in the brain, liver and gills. In addition, we also studied the expression of hepatic insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein 1 (IGFBP-1) and growth hormone (GH) receptor, while cortisol receptor (CR) and cytochrome P450 1A (CYP1A) gene expression were assayed in both the liver and gills. Histological analysis revealed PVC-MPs in the intestines at 0.1 and 0.5 mg/L, along with substantially shorter villi. The gills appeared undamaged by PVC-MPs exposure and had limited or no effect to antioxidant activity, Na+/K+-ATPase and H+-ATPase activity or plasma ion levels, but there was a prominent upsurge of the detoxification enzymes glutatione S-transferase (GST) activity and CYP1A expression. Livers showed inflammation and some occurrences of hemorrhaging and necrosis at 0.5 mg/L. While the brain showed some evidence of oxidative damage, the liver was the most susceptible to oxidative damage, based on increased MDA, H2O2 and various antioxidant enzymes. Hepatic expression of IGFBP-1 and GH receptor were significantly downregulated at 0.5 mg/L while CR was upregulated. Results indicate that exposure to environmentally relevant PVC-MP can cause oxidative damage in the brain and liver, adverse histomorphological changes to the intestine and liver and alter the gene expression in goldfish. [Display omitted] •Virgin microplastics (MPs) at 0.5 mg/L induced oxidative damage to brain and liver.•Anti-oxidative response was differentially modulated in brain, liver and gills.•Histology revealed MPs in intestines at 0.1 and 0.5 mg/L, with substantially shortened villi.•0.5 mg/L MPs reduced growth regulating genes receptors and binding proteins expression.•PVC-MPs had no effect on gills Na+/K+-ATPase and H+-ATPase activities, and ions status.