Project description:Purpose:Sipunculus nudus is a marine organism with high application value, and the fibrinolytic enzyme (SNFE) extracted from the visceral homogenate has been proved to have an antithrombotic effect by experiments. MicroRNAs(MiRNAs) play an important role in the molecular mechanisms related to plasmin. However, the research on plasmin-related miRNA of Sipunculus nudus is relatively rare. Methods:In this paper, high-throughput sequencing technology was used to sequence and analyze the small RNA and transcriptome of Sipunculus nudus. Conclusion:After data analysis, 198 known miRNAs were identified and 46 new miRNAs were predicted, followed by statistical analysis of miRNA base preference. At the same time, 76 miRNAs differentially expressed in different tissues were found, and a total of 76 known and new miRNAs were predicted for target genes, from which 7,161 candidate target genes were obtained. In addition, we found that six plasmin-related target genes were significantly annotated with 28 GO terms, and three plasmin-related target genes were rich in eight KEGG biological pathways. Finally, four joint regulatory networks including four candidate target genes, 32 differentially expressed miRNA and related proteins were constructed according to the four related species, and it was found that there existed interactions between the candidate target genes Cluster-15745.8440 and Cluster-3821.0 with unclear mechanisms.This study will provide a reference for in-depth exploration of the regulatory relationship between the plasmin-related genes and miRNA in Sipunculus nudus and understanding the molecular mechanisms related to plasmin in Sipunculus nudus.
Project description:The peanut worm (Sipunculus nudus) is an economically important fishery resource in China. To determine how dietary carbohydrate and protein levels affects the growth performance of juvenile S. nudus and identify the mechanisms underlying observedpatterns, five isoenergetic and isolipidic diets with different levels of carbohydrate and protein were formulated and fed to juvenile S. nudus; the experimental groups were referred to as EG1, EG2, EG3, EG4, and EG5, respectively. After 90 days of feeding, S. nudus had significantly lower survival rates when fed D5 compared with other diets (P < 0.05), and the highest survival rate was observed in EG2 individuals. The weight gain rate and specific growth rate were significantly higher in EG2 compared with the other groups (P < 0.05). Metabolomic profiling using LC–MS revealed 83 significantly differential metabolites (POS: 59; NEG: 24), which were identified via an in-house MS2 database. Pathway analysis indicated that the significantly different metabolites were involved in 22 metabolic pathways (POS: 9; NEG: 13), including tyrosine, phenylalanine, and tryptophan biosynthesis; phenylalanine metabolism; D-glutamate and D-glutamine metabolism; proline and arginine metabolism; aspartate, alanine, and glutamate metabolism; and aminoacyl-tRNA biosynthesis. These analyses implied that the biosynthetic capabilities of juvenile S. nudus were greater in the EG2. The results of this research enhance our understanding of the effects of dietary carbohydrate and protein levels on the growth performance of juvenile S. nudus.
Project description:Sipunculus nudus, an old marine species, has great potential for use as functional seafood due to its various bioactivities. Its potential antithrombotic activity pushed us to isolate the bio-active components bio-guided by tracking fibrinolytic activity. As a result, a novel protease named as SK (the kinase obtained from S. nudus) was obtained, which possessed a molecular weight of 28,003.67 Da and 15 N-terminal amino acid sequences of PFPVPDPFVWDTSFQ. SK exerted inhibitory effects on thrombus formation through improving the coagulation system with dose-effect relationship within a certain range. Furthermore, in most cases SK got obviously better effect than that of urokinase. With the help of untargeted mass spectrometry-based metabolomics profiling, arachidonic acid, sphingolipid, and nicotinate and nicotinamide mechanism pathways were found to be important pathways. They revealed that the effect mechanism of SK on common carotid arterial thrombosis induced by FeCl? was achieved by inhibiting vessel contraction, platelet aggregation, adhesion, and release, correcting endothelial cell dysfunction and retarding process of thrombus formation. This study demonstrated SK was a promising thrombolytic agent on the basis of its comprehensive activities on thrombosis, and it should get further exploitation and utilization.