Screening And Identification Of Toxic Proteins In Jellyfish Which Causing Inflammation

With the global warming and the increase of marine pollutants,the outbreak growth of jellyfish has led to an increase incidence of jellyfish sting in coastal areas.Jellyfish belong to the cnidaria and are widely distributed in the seas of the world.When they are stimulated by the outside world,they will release a large amount of mucus and nematocyst venom as a defense measure.Common symptoms of human skin after the contact with these substances are skin inflammatory reactions such as redness,itching,and severe cases can cause systemic poisoning reactions and even death.The skin symptoms caused by jellyfish stings are clinically called jellyfish dermatitis.Inflammatory reaction accompanies the whole process of jellyfish dermatitis,which seriously affects people's daily life and health.Due to the variety of jellyfish,easy to autolyze after fished,the small amount and easy to inactivate of the toxin lead to its difficulty in extraction.And the toxin protein in toxin are difficult to identify,which also causes the lack of specific drugs for treating dermatitis caused by jellyfish injury.In this paper,omics methods was used to explore proteins in different jellyfish that cause skin inflammation,in order to find key proteins that play the same role in the two jellyfish.1.A collection method for the Aurelia coerulea jellyfish was established.A.coerulea jellyfish were stimulated by removing them from environmental seawater.Secreted mucus during the six time periods of 0-10 min,10-20 min,20-30 min,30-40 min,40-50 min,50-60 min and tissue samples were collected.The results showed that the amount of mucus in the jellyfish gradually decreased in the first 30 min,and gradually increased in the last 30 min.Considering the effects of autolysis and seawater,the mucus collected during the 10-20 min period was selected for follow-up studies.2.Screening and identification of self-protective proteins in the A.coerulea jellyfish.Differential proteins in jellyfish mucus and tissue were analyzed by liquid chromatography coupled with tandem mass spectrometry and ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry combined with proteomics and metabolomics,and self-protective proteins were screened and identified by bioinformatics.A total of 2,421 and 1,208 proteins were identified in tissue homogenate and secreted mucus,respectively.Gene Ontology analysis showed that the mucus-enriched proteins were mainly located in extracellular or membrane-associated regions,while the tissue-enriched proteins were distributed throughout intracellular compartments.Tryptamine,among 16 different metabolites,increased with the largest-fold change value of 7.8 in mucus,was consistent with its involvement in the KEGG pathway ‘tryptophan metabolism'.The paper identified 11 metalloproteinases,4 serpins,3 superoxide dismutases and 3 complements.It can be inferred that their presence was speculated to be related to self-protective defense.3.By the BD-4 polar jellyfish omics study method to find the common proteins with A.coerulea jellyfish.The BD-4 jellyfish samples were analyzed using de novo transcription and proteomics methods.The identified proteins were compared with toxin databases to screen toxin-related proteins,and bioinformatics analysis methods were used to analyze the protein sequence,3D structure and molecular evolution relationship.BD-4 jellyfish generated a total of 32,247 transcripts,of which NR database annotated 12,955(40.16%)transcripts,SwissProt database annotated 10,882(33.75%)transcripts,GO database annotated 4,951(15.35%)transcripts,COG database annotated 10,159(18.75%)transcripts,KEGG database annotated 4,901(15.20%)transcripts,and eggNOG datebase annotated 12,438(38.57%)transcripts.A total of 79 toxin-related protein sequences were screened out from the identified proteins and classified into eight categories according to their molecular functions.It was speculated that there were major components in these toxic proteins that causing skin inflammation.This study explored the collection method of A.coerulea jellyfish and determines the optimal collection time.A composition profile of proteins and metabolites in stress-induced mucus and tissue homogenate of A.coerulea jellyfish was provided for the first time.Self-protective proteins(also known as potential proteins causing inflammation)in stress-induced mucus were screened out.The gene and protein of polar jellyfish were studied by omics method,and the possible toxic proteins were screened out.According to the protein screening results of two different types of jellyfish,proteins with metalloproteinase activity may be the key component to skin inflammation.