Proteomic analysis provides insights into the function of Polian vesicles in the sea cucumber A postichopus japonicus post-evisceration

The Polian vesicle is the main accessory structure in the water vascular system of sea cucumbers.It can function to hold water vascular fluid under slight pressure and act as a hematopoiesis,excretory,and inflammatory response organ.Being the only organ to remain after evisceration,the Polian vesicle may function in the survival and regeneration of sea cucumber.We performed Tandem Mass Tag(TMT)-based proteomics to identify how proteins in the Polian vesicle of Apostichopus japonicus respond to evisceration.Among the 8453 proteins identified from vesicle samples before evisceration(PVOh)and at 6-h post-evisceration(PV6h)and 3-d post-evisceration(PV3d),we detected 222 differentially abundant proteins(DAPs).Most of the annotated DAPs were associated with cell growth and proliferation,immune response and wound healing,substance transport and metabolism,cytoskeleton/cilia/flagella,extracellular matrix,energy production and conversion,protein synthesis and modification,and signal recognition and transduction.Compared with PVOh,fewer DAPs were identified at PV6h,and more DAPs were found at PV3d,and these DAPs were widely distributed among multiple biological processes.Our results indicate that a wide range of biological processes was induced in Polian vesicles in response to evisceration.In particular,Polian vesicles may play important roles in the re storation of coelomocyte s,immune defense,and wound healing in sea cucumber.We propose that the Polian vesicle may be involved in visceral regeneration through nutrition and energy supply and by promoting dedifferentiation and migration.Together,these results provided new insights into the function of the Polian vesicle in A.japonicus post-evisceration.