[Porcine epidemic diarrhea virus promotes self-replication by inducing reprogramming of glucose metabolism in host...

The aim of this study is to explore how porcine epidemic diarrhea virus (PEDV) infection induces reprogramming of glucose metabolism in host cells and its impact on viral replication. We designed a control group and an infection group [infection of porcine intestinal epithelial cells (IPEC-J2) with PEDV]. First, we determined the infection time and dose of the virus by observing the PEDV titer and the expression of the N protein. Then, through proteomic comparative analysis, we studied the enriched differentially expressed proteins, key proteins, and key metabolic pathways in PEDV-infected cells. RT-qPCR and Western blotting were employed to verify the protein or gene expression of key enzymes in the glycolysis and tricarboxylic acid (TCA) cycle pathways in PEDV-infected cells. Finally, we clarified the impact of PEDV-induced glycolytic changes on viral replication by measuring the content of glucose, ATP, and lactic acid, as well as the expression of glucose transporters (SGLT-1 and GLUT-2) and PEDV N protein in cells. The results indicated that the optimal infection time of PEDV in IPEC-J2 was 48 h and the optimal multiplicity of infection was 1. Proteomics results showed that 342 differentially expressed proteins were screened out and mainly enriched in pathways such as glycolysis, digestion and absorption of carbohydrates, and lipid metabolism. PEDV infection upregulated the protein levels of key glycolysis enzymes HKII (P<0.05), LDHA, and PKM (P<0.01) in IPEC-J2 and the gene transcription level of PFK (P<0.01), while downregulating the gene transcription levels of key enzymes CS, OGDH, and IDH in the TCA cycle pathway (P<0.01). In addition, PEDV infection increased intracellular lactate content (P<0.01), decreased the ATP content (P<0.01), upregulated the expression levels of SGLT-1 and GLUT-2 (P<0.05, P<0.01). Pre-treatment of IPEC-J2 with the glycolysis inhibitor 2-deoxy- d-glucose (2-DG) reduced the intracellular expression of PEDV N protein (P<0.05). In conclusion, PEDV infection can induce reprogramming of glucose metabolism in host cells and enhance the replication of the virus. This is manifested as the activation of the glycolysis pathway and the obstruction of the TCA cycle and oxidative phosphorylation. PEDV promotes glucose uptake and up-regulate the expression of key enzymes in the glycolysis pathway to induce reprogramming of glucose metabolism, thus promote its efficient replication in host cells. This study confirms that PEDV infection can induce reprogramming of host cell glucose metabolism and promote viral replication by activating aerobic glycolysis, providing new insights and approaches for the targeted treatment and prevention of PEDV infection.