Activation of the unfolded protein response via PERK-ATF4 signalling in deoxynivalenol- and PRRSV-co-exposed MARC-145 cells.

Importance

Deoxynivalenol (DON) is a prevalent mycotoxin that is highly toxic to animals, particularly pigs. Porcine reproductive and respiratory syndrome virus (PRRSV) is a major swine pathogen with high infectivity and severe clinical outcomes, but the mechanisms underlying the host cell responses to co-exposure of DON and PRRSV remain unclear.

Objective

This study examined the effects of the co-exposure of Marc-145 cells with DON and PRRSV.

Methods

A DON- and PRRSV-co-exposed MARC-145 cells model was established, and transcriptomic/proteomic sequencing combined with Western blot and immunofluorescence assays explored the mechanism disrupting microenvironmental homeostasis.

Results

Integrated transcriptomic and proteomic analyses showed that the PRRSV infection and DON co-exposure enriched four molecular function categories in Gene Ontology and one Kyoto Encyclopedia of Genes and Genomes pathway. Protein-protein interaction network analysis identified key hub proteins that were central to the unfolded protein response (UPR) and endoplasmic reticulum stress: glucose-regulated protein 78 (GRP78), activating transcription factor 6 beta (ATF6b), inositol-requiring enzyme 1α (IRE1α), activating transcription factor 4 (ATF4), and protein kinase R-like endoplasmic reticulum kinase (PERK). Experimental validation showed that co-exposure elevated the ATF6b, phosphorylated PERK, and phosphorylated eukaryotic initiation factor-2α levels, while reducing GRP78, IRE1α, ATF6b nuclear form, ATF4, and growth arrest and DNA damage-inducible protein 34, thereby activating the UPR.

Conclusions

AND RELEVANCE Ultimately, co-exposure to DON and PRRSV disrupted the intracellular microenvironment in Marc-145 cells by modulating the PERK-ATF4 signaling pathway, accompanied by reducing the ability of host cells to replicate the virus.