In vivo mechanism of action of matrix metalloprotease (MMP) in the autolysis of sea cucumber (Stichopus japonicus)

摘要

Matrix metalloprotease (MMP) is the key endogenous protease that boosts the autolysisof sea cucumber, while its action and mechanism in vivo are still unclear. MMPinhibitor (1,10-phenanthroline) was injected into coelomic cavity of sea cucumber(Stichopus japonicus) and its effects on autolysis and mechanism of action were investigatedfor the first time by using scanning electron microscopy, multi-functionalin vivo imaging system, and confocal laser scanning microscopy. In response to externalstimuli, the level of Ca~(2+) in live sea cucumber dermis increased, which mayactivate MMP activity. MMP inhibitor could diffuse from coelomic cavity into bodywall and significantly prevented the activation of MMP by chelating Ca~(2+), and thus,retarded the autolysis of fresh sea cucumber by preventing degradation of interfibrillarproteoglycan bridges between adjacent collagen fibrils. This work providesinformation toward understanding the mechanism behind the sea cucumber autolysisand demonstrate a potential approach to prevent the autolysis.