Studies On The Toxicity Mechanism Of Cadmium And Inorganic Arsenic In Portunus Trituberculatus

In the past two decades,with the vigorous economic development,industries in coastal areas have risen rapidly,and numerous heavy metal processing and smelting enterprises have developed rapidly.A large amount of industrial sewage carrying heavy metals has been discharged into the marine environment,making China coastal waters heavy metal pollution increasingly serious,it has caused the coastal waters to become a giant carrier of heavy metal pollutants.Unlike organic pollutants,heavy metals under the condition of nature can't effectively decomposition using,easily accumulate in the Marine environment,has the characteristics of refractory and high-risk rationality,accumulated to a certain concentration in the Marine environment,can produce toxic to Marine organisms,and potential damage to the Marine ecological system.In this study,based on the current status of heavy metal pollution in the coastal waters of China,the typical heavy metal cadmium(Cd)and metalloid arsenic(As)were selected as exposure pollutants.Portunus trituberculatus was used as the research object.The use of ultra-high performance liquid chromatography-based time-of-flight mass spectrometry Non-targeted metabolomics,proteomics based on isotope-labeled relative and absolute quantitative technology(TMT)and other molecular biology are used as research tools to explore the toxicity mechanism of 0.05 mg/L Cd²⁺,0.3 mg/L As(?)and As(?)exposure to Portunus trituberculatus for 96 h.The research results provide theoretical basis and technical support for the screening of biological effect markers and toxic effects of environmental pollutants.The results of the study are as follows:(1)Effects of Cd and As on the antioxidant system of Portunus trituberculatusUsing antioxidant enzyme activity as an indicator to carry out As(?),As(?)and Cd²⁺stress experiments on the gill tissue,muscle tissue and gonadal tissue of Portunus trituberculatus.The results showed that the gill tissue,muscle tissue,and gonadal tissues all changed their antioxidant under the treatment of As(?),As(?)and Cd²⁺.After exposure to As(?),As(?)and Cd²⁺,SOD in the gill tissue,muscle tissue,and gonad tissue of Portunus trituberculatus showed that with the prolonged stress time,the SOD activity increased.This is the adaptive response of Portunus trituberculatus to heavy metals.It is an acute detoxification measure that adjusts SOD activity to respond to the reactive oxygen species(ROS)produced by heavy metal stress;MDA content increases with the prolonged stress time,indicating that As(?),As(?),Cd²⁺cause lipid oxidative damage to Portunus trituberculatus;The decrease in GSH content indicates that Portunus trituberculatus has activated its own protective measures in response to oxidative stress caused by heavy metal stress.(2)Study on the Toxicity Mechanism of Cd on Portunus trituberculatusMetabolomics studies based on LC-MS technology showed that Portunus trituberculatus obtained a total of 1032 metabolites after exposure to Cd²⁺.Compared with the control group,59 differential metabolites were screened in the Cd exposure group,of which 38 were up-regulated and 21 were down-regulated.The annotation results of KEGG and HMDB showed that the content of coenzyme Q,prostaglandin E2,glutamate,phosphocholine,ATP,alanine and leukotrienes changed significantly.Using proteomics based on TMT technology to study protein changes in Portunus trituberculatus,a total of 102 differential proteins were obtained.Compared with the control group,28 differential proteins were up-regulated and 74 differential proteins were down-regulated.The function and pathway analysis of the differential proteins found that Cd exposure inhibited the expression of phosphomannose isomerase in Portunus trituberculatus,disrupted the N-glycosylation process to inhibit glycolysis,and promoted the amino acid,protein and Lipid metabolism;induced severe immunity,oxidative stress and signal transduction in Portunus trituberculatus;interfered with the stability of the cytoskeleton of Portunus trituberculatus.This study shows that the research contents of proteomics and metabolomics methods mutually verify and complement each other,and can better explore the toxic mechanism of heavy metal pollutants in seawater on marine organisms at the molecular level.(3)Study on the Toxicity Mechanism of As on Portunus trituberculatusMetabolomics studies based on LC-MS technology showed that a total of 1989metabolites were obtained from Portunus trituberculatus after being exposed to As(?);compared with the control group,the As(?)exposure group screened out 100differential metabolites,among which 74 were up-regulated and 26 were down-regulated;the annotation results of KEGG and HMDB show that the content of metabolites such as arginine,alanine,glycine,ATP,kynurenine and leukotrienes have changed significantly;A total of 1049 metabolites were obtained from Portunus trituberculatus after As(?)exposure.Compared with the control group,59 differential metabolites were screened in the As(?)exposure group,of which 37 were up-regulated and 22 were down-regulated.The annotation results of KEGG and HMDB showed that the content of metabolites such as arginine,alanine,glycine,glutamic acid and glycerophospholipid changed significantly.Using proteomics based on TMT technology to study protein changes in Portunus trituberculatus,compared with the control group,the As(?)exposure group screened out 407 differential proteins,including 133 up-regulated proteins and 274 down-regulated proteins;144 differential proteins were identified in the As(?)exposure group,and the numbers of up-regulated and down-regulated proteins were 35 and 109,respectively.The function and pathway analysis of the differential proteins found that the effects of As(?)and As(?)exposure on Portunus trituberculatus were manifested in the following aspects:As(?)and As(?)exposure inhibited the glycolysis of Portunus trituberculatus;promoted the lipid metabolism of Portunus trituberculatus and interfered with it;affects the protein degradation/synthesis of Portunus trituberculatus;affects the signal pathways related to extracellular matrix and Ca²⁺homeostasis of Portunus trituberculatus;affects the cytoskeleton structure of Portunus trituberculatus;induces the oxidative stress and immunity of Portunus trituberculatus reaction.