Responses of lipid metabolism and lipidomics in the hepatopancreas of Pacific white shrimp Litopenaeus vannamei to microcystin-LR exposure

Microcystin-LR (MC-LR) is a toxic substance that threatens the health of aquatic animals. Hepatopancreas is the target organ of MC-LR toxicity. In this study, we investigated the effects of MC-LR on hepatopancreas lipid metabolism and lipidomic responses in Litopenaeus vannamei. After MC-LR exposure for 72 h, the hepatopancreas showed obvious tissue damage, and the activities of several lipase isoenzymes were decreased. Furthermore, the relative gene expression levels of lipolysis (CPT1, AMPK alpha), lipogenesis (SREBP, FAS, ACC, 6PGD), and long-chain fatty acid beta-oxidation (ACDL, ACDVL, ACBP) were increased. MC-LR exposure also affected lipidomics homeostasis. Specifically, the levels of glycerophospholipids (phosphatidylcholine, phosphatidic acid, lyso-phosphatidylcholine, lyso-phosphatidylethanolamine, lysophosphatidylglycerol), sphingolipids (sphingomyelin and ceramides) and cholesteryl ester were increased, and those of phosphatidylinositol and triglyceride were decreased. The significantly altered lipid molecules were mainly associated with the pathways of lipid and fatty acid metabolism and autophagy. These results reveal that MC-LR exposure influences lipid metabolism and lipidomic homeostasis in the shrimp hepatopancreas.