Untargeted metabolomics investigating porcine reproductive and respiratory syndrome virus biomarkers of serum-derived exosomes in piglets infected with PRRSV NADC30-like CHsx1401

Abstract

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most severe swine diseases in the pig industry. The identification of biomarkers for PRRSV infection is valuable for controlling, eliminating, and treating PRRSV. This study utilized the ultra-performance liquid chromatography–mass spectrometry metabolite profiling platform to identify differential metabolites in exosomes between the control and NADC30-like PRRSV strain infected pigs. Using multivariate analysis combined with univariate analysis, unsupervised principal component analysis and orthogonal partial least squares discriminant analysis models were constructed between the groups. A total of 41 differential metabolites were detected, with 14 upregulated and 27 downregulated metabolites with PRRSV infection. MetaboAnalyst and Kyoto Encyclopedia of Genes and Genomes were used to identify potentially relevant significant pathways, and a receiver operating characteristic curve was used to quantify the predictive performance of differential metabolites. The results indicated that tryptophan-related L-kynurenine, 5-hydroxytryptophan, and D (+)-tryptophan significantly increased among PRRSV infected groups, which may play an important role in the progression of PRRSV infection. Metabolites related to amino acid synthesis and metabolism, including 2-arachidonoylglycerol Lysopcs and phosphatidylcholines may also contribute to the lack of immune protection in piglets after PRRSV infection. Moreover, L-kynurenine and taurocholic acid may serve as potential biomarkers for early diagnosis or drug targeting of PRRSV. Overall, these findings provide an important reference to our understanding of PRRS pathogenesis and immune or protective responses during PRRSV acute infection in the host.