scholarly journals Exosomal miR-224 contributes to hemolymph microbiota homeostasis during bacterial infection in crustacean

2021 ◽  
Vol 17 (8) ◽  
pp. e1009837
Author(s):  
Yi Gong ◽  
Xiaoyuan Wei ◽  
Wanwei Sun ◽  
Xin Ren ◽  
Jiao Chen ◽  
...  

It is well known that exosomes could serve as anti-microbial immune factors in animals. However, despite growing evidences have shown that the homeostasis of the hemolymph microbiota was vital for immune regulation in crustaceans, the relationship between exosomes and hemolymph microbiota homeostasis during pathogenic bacteria infection has not been addressed. Here, we reported that exosomes released from Vibrio parahaemolyticus-infected mud crabs (Scylla paramamosain) could help to maintain the homeostasis of hemolymph microbiota and have a protective effect on the mortality of the host during the infection process. We further confirmed that miR-224 was densely packaged in these exosomes, resulting in the suppression of HSP70 and disruption of the HSP70-TRAF6 complex, then the released TRAF6 further interacted with Ecsit to regulate the production of mitochondrial ROS (mROS) and the expression of Anti-lipopolysaccharide factors (ALFs) in recipient hemocytes, which eventually affected hemolymph microbiota homeostasis in response to the pathogenic bacteria infection in mud crab. To the best of our knowledge, this is the first document that reports the role of exosome in the hemolymph microbiota homeostasis modulation during pathogen infection, which reveals the crosstalk between exosomal miRNAs and innate immune response in crustaceans.

2020 ◽  
Author(s):  
Yi Gong ◽  
Xiaoyuan Wei ◽  
Wanwei Sun ◽  
Xin Ren ◽  
Jiao Chen ◽  
...  

AbstractThe modulation of hemolymph microbiota homeostasis is vital for the marine invertebrate innate immunity, while growing evidence shows that exosomes could serves as anti-bacterial immune factors, however, the relationship between exosomes and hemolymph microbiota homeostasis during pathogenic bacteria infection has not been addressed. Here, we determined that exosomes released from Vibrio parahaemolyticus-infected Scylla paramamosain (mud crabs) could reduce the mortality of the host during the infection by maintaining the homeostasis of hemolymph microbiota. We further confirmed that miR-224 was densely packaged in these exosomes and targeting to HSP70, which resulted in disruption of the HSP70-TRAF6 complex to release TRAF6 that allows it to interact with Ecsit. The interaction of TRAF6 with Ecsit regulates the production of mitochondrial ROS (mROS) and Anti-lipopolysaccharide factors (ALFs) expression in recipient hemocytes, which affects homeostasis of hemolymph microbiota in response to the pathogenic bacteria infection in mud crab. To the best of our knowledge, this is the first document that reports the role of exosome in the homeostasis of hemolymph microbiota during pathogen infection and a novel regulatory mechanism and crosstalk between exosomal miRNAs and innate immune response in crustaceans.Author summaryExosomes are small membrane vesicles of endocytic origin which are widely involved in the regulation of a variety of pathological processes in mammals. Yet, although the antibacterial function of exosomes has been discovered for many years, the relationship between exosomes and hemolymph microbiota homeostasis remains unknown. In the present study, we identified the miRNAs packaged by exosomes that were possibly involved in Vibrio parahaemolyticus infection by modulating hemolymph microbiota homeostasis in crustacean mud crab Scylla paramamosain. Moreover, it was found that miR-224 was densely packaged in exosomes after Vibrio parahaemolyticus challenge, resulting in the suppression of HSP70 and disruption of the HSP70-TRAF6 complex in recipient hemocytes, then the released TRAF6 was further interacted with Ecsit to regulate ROS and ALFs levels, which eventually affected hemolymph microbiota homeostasis to cope with pathogenic bacteria infection. Our finding is the first to reveal the relationship between exosomes and hemolymph microbiota homeostasis in animals, which shows a novel molecular mechanism of invertebrate resistance to pathogenic microbial infection.


2021 ◽  
Author(s):  
Yi Gong ◽  
Jiao Chen ◽  
Yalei Cui ◽  
Sheng-Kang Li

As we known, Caspase 2 is widely studied for its apoptosis regulatory function in mammals. However, despite the fundamental role of apoptosis during the anti-viral immune response, the relationship between Caspase 2 and virus infection has not been extensively explored in invertebrates, whether miRNAs are involved in this process also remains unclear. To address this issue, the miRNA-mediated regulation of Caspase 2 in mud crab Scylla paramamosain was characterized in this study. The results suggested that Sp-Caspase 2 could suppress white spot syndrome virus (WSSV) infection via apoptosis induction. The further data showed that Caspase 2 was directly targeted by miR-2 in mud crab. Silencing or overexpression of miR-2 could affect apoptosis and WSSV replication through regulating the expression level of Caspase 2. Taken together, all these results demonstrated the crucial role of miR-2-Caspase 2 pathway in the innate immunity of mud crab and revealed a novel mechanism during anti-viral immune response in marine invertebrates.


2021 ◽  
Vol 118 ◽  
pp. 213-218
Author(s):  
Chang-Hong Cheng ◽  
Xiu-Ze Liu ◽  
Hong-Ling Ma ◽  
Guang-Xin Liu ◽  
Yi-Qin Deng ◽  
...  

2021 ◽  
Vol 8 ◽  
Author(s):  
An Liu ◽  
Wenyuan Shi ◽  
Dongdong Lin ◽  
Haihui Ye

C-type allatostatins (C-type ASTs) are a family of structurally related neuropeptides found in a wide range of insects and crustaceans. To date, the C-type allatostatin receptor in crustaceans has not been deorphaned, and little is known about its physiological functions. In this study, we aimed to functionally define a C-type ASTs receptor in the mud crab, Scylla paramamosian. We showed that C-type ASTs receptor can be activated by ScypaAST-C peptide in a dose-independent manner and by ScypaAST-CCC peptide in a dose-dependent manner with an IC50 value of 6.683 nM. Subsequently, in vivo and in vitro experiments were performed to investigate the potential roles of ScypaAST-C and ScypaAST-CCC peptides in the regulation of ecdysone (20E) and methyl farnesoate (MF) biosynthesis. The results indicated that ScypaAST-C inhibited biosynthesis of 20E in the Y-organ, whereas ScypaAST-CCC had no effect on the production of 20E. In addition, qRT-PCR showed that both ScypaAST-C and ScypaAST-CCC significantly decreased the level of expression of the MF biosynthetic enzyme gene in the mandibular organ, suggesting that the two neuropeptides have a negative effect on the MF biosynthesis in mandibular organs. In conclusion, this study provided new insight into the physiological roles of AST-C in inhibiting ecdysone biosynthesis. Furthermore, it was revealed that AST-C family peptides might inhibit MF biosynthesis in crustaceans.


2019 ◽  
Vol 116 (50) ◽  
pp. 25106-25114 ◽  
Author(s):  
Wenqian Li ◽  
Jun Yan ◽  
Yan Yu

Receptors of innate immune cells function synergistically to detect pathogens and elicit appropriate immune responses. Many receptor pairs also appear “colocalized” on the membranes of phagosomes, the intracellular compartments for pathogen ingestion. However, the nature of the seemingly receptor colocalization and the role it plays in immune regulation are unclear, due to the inaccessibility of intracellular phagocytic receptors. Here, we report a geometric manipulation technique to directly probe the role of phagocytic receptor “colocalization” in innate immune regulation. Using particles with spatially patterned ligands as phagocytic targets, we can decouple the receptor pair, Dectin-1 and Toll-like receptor (TLR)2, to opposite sides on a single phagosome or bring them into nanoscale proximity without changing the overall membrane composition. We show that Dectin-1 enhances immune responses triggered predominantly by TLR2 when their centroid-to-centroid proximity is <500 nm, but this signaling synergy diminishes upon receptor segregation beyond this threshold distance. Our results demonstrate that nanoscale proximity, not necessarily colocalization, between Dectin-1 and TLR2 is required for their synergistic regulation of macrophage immune responses. This study elucidates the relationship between the spatial organization of phagocytic receptors and innate immune responses. It showcases a technique that allows spatial manipulation of receptors and their signal cross-talk on phagosomes inside living cells.


Sign in / Sign up

Export Citation Format

Share Document