Neural excitotoxicity and the toxic mechanism induced by acute hypoxia in Chinese mitten crab (Eriocheir sinensis)

Cong Zhang; Xiaodan Wang; Jiaqi He; Yuxing Huang; Qincheng Huang; Chuanjie Qin; Jianguang Qin; Liqiao Chen

doi:10.1016/j.aquatox.2022.106131

Neural excitotoxicity and the toxic mechanism induced by acute hypoxia in Chinese mitten crab (Eriocheir sinensis)

Aquat Toxicol. 2022 Apr:245:106131. doi: 10.1016/j.aquatox.2022.106131. Epub 2022 Mar 1.

Authors

Cong Zhang¹, Xiaodan Wang¹, Jiaqi He¹, Yuxing Huang¹, Qincheng Huang¹, Chuanjie Qin², Jianguang Qin³, Liqiao Chen⁴

Affiliations

¹ Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, PR China.
² Key Laboratory of Sichuan Province for Fishes Conservation and Utilization in the Upper Reaches of the Yangtze River, Neijiang Normal University, Sichuan, 641100, PR China.
³ College of Science and Engineering, Flinders University, Adelaide, SA, 5001, Australia.
⁴ Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, PR China. Electronic address: lqchen@bio.ecnu.edu.cn.

PMID: 35255275
DOI: 10.1016/j.aquatox.2022.106131

Abstract

Hypoxia can induce neural excitotoxicity in mammals, but this adverse effect has not been investigated in aquatic animals to date, especially in crustaceans. This study explored the induction effect and toxic mechanism of acute hypoxia stress (1.0 ± 0.1 mg dissolved oxygen /L) for 24 h on neural excitotoxicity in juvenile Chinese mitten crab, Eriocheir sinensis. The results showed that hemolymph glucose and serum lactic acid content were significantly increased, and the mRNA expression of crustacean hyperglycemic hormone and hypoxia-inducible factor 1α were significantly up-regulated in the hypoxia group compared with control. RNA-Seq results confirmed that acute hypoxia stress had a more significant impact on carbohydrate metabolism than lipid and protein metabolism. In addition, the TUNEL assay showed that the apoptosis rate of nerve cells was significantly higher in the hypoxia group than in the control, and similar trends were observed in the expression of apoptosis-related genes. RNA-Seq results also showed that acute hypoxia stress-induced neuronal apoptosis by regulating multiple apoptosis-related pathways. Moreover, free glutamate and GABA contents in the nerve tissue of thoracic ganglia were significantly higher in the hypoxia group than in the control group. Furthermore, the mRNA expression of NMDA related receptors was significantly up-regulated in the hypoxia group compared with the control. Similar trends were observed in the expression of calcium-dependent degrading enzymes and endogenous antioxidant-related proteins or enzymes. Meanwhile, the mRNA expression level of high-affinity neuronal glutamate transporter in the hypoxia group was significantly up-regulated compared with the control, whereas the vesicular glutamate transporter was significantly down-regulated. Furthermore, NMDA-R antagonists (MK-801 and Ro25-6981) injection showed that NMDA-R served as the bridge and core position of glutamate-induced neural neurotoxicity. This study provides a new perspective and theoretical guidance for exploring the regulation of hypoxic tolerance in E. sinensis.

Keywords: Acute hypoxia stress; Eriocheir sinensis; NMDA-R antagonists; Neural excitotoxicity; RNA-Seq.

MeSH terms

Animals
Brachyura*
China
Glucose / metabolism
Hemolymph
Hypoxia / metabolism
Mammals
Water Pollutants, Chemical* / toxicity

Substances

Water Pollutants, Chemical
Glucose