Spatiotemporal Variation of Residual Cortisol Obstructs Nutrient Acquisition in Animal-Derived Foods by Perturbing Glycerophospholipid Metabolism.

Abstract

Cortisol is inevitably secreted by pigs due to the physical and psychological stressors produced by mixed group transportation and preslaughter handling. Accumulated cortisol in animal tissues enters the human body through the food chain and entails potential risks to human health. An integrated lipidome and proteome analysis was conducted to investigate the effect of the spatiotemporal variation of residual cortisol on nutrient acquisition in pork. A total of 55 crucial lipid molecules associated with cortisol residue were identified based on debiased sparse partial correlation analysis. Label-free proteomics was applied to screen 58 differentially abundant proteins (including phospholipase A2, lysophosphatidylcholine acyltransferase, and CTP:phosphocholine cytidylyltransferase), indicating that cortisol residue perturbed the glycerophospholipid biosynthetic process and glycerophospholipid metabolic process. Cortisol induced downregulations of cPLA2 encoding genes and decreased phospholipase A2 activity, resulting in the bioaccumulation of phosphatidylethanolamine (from 36.86 to 43.18 mg kg-1). Cortisol increased the activity of CTP:phosphocholine cytidylyltransferase by improving the availability of fatty acids and aggregating the inactive L-form (lipid-independent form) to the active H-form (lipid-associated form). The metabolic pathways perturbed by cortisol resulted in phosphatidylcholine degradation (from 93.73 to 58.28 mg kg-1) and lysophosphatidylcholine accumulation (from 3.39 to 5.16 mg kg-1). These findings indicated that cortisol residue deteriorated meat quality and obstructed nutrient acquisition in animal-origin foods.