A novel role of PvUCP4 in Penaeus vannamei in response to Vibrio alginolyticus challenge

Abstract

Mitochondria are the energy production and metabolic centers of cells. About 90 % of reactive oxygen species come from mitochondria. Uncoupling proteins (UCPs) have a protective effect against oxidative stress in mitochondria. But this regulatory mechanism remains poorly understood in crustaceans. Here, we investigated the mechanism of PvUCP4 under vibrio alginolyticus challenge. Transcriptome analysis revealed that energy metabolism is a key pathway in the shrimp's immune response. Interestingly, PvUCP4, a mitochondrial uncoupling protein, was found to be inhibited, indicating its potential involvement in the shrimp's resistance to V. alginolyticus. Silencing PvUCP4 upregulates antioxidant enzyme gene expression, including SOD, CAT, and GPX. However, pretreatment with the ROS scavenger N-acetylcysteine revealed that silencing PvUCP4 had no effect on the expression of antioxidant genes. Pretreatment with LPS, a bacterial cell wall component, can rescue partial inhibition of DJ-1/NF-κB signaling pathway related genes caused by overexpression of PvUCP4. In addition, inhibiting PvUCP4 increased the expression of apoptosis-related genes and induced apoptosis. Ultimately, silencing PvUCP4 reduced the survival rate of shrimp under V. alginolyticus stress. Collectively, these findings suggest that PvUCP4 is neither dependent on the antioxidant enzyme system for its antioxidant effects nor on the negative feedback regulation of the DJ-1 pathway.