Shenglong Wu

Porcine epidemic diarrhea virus (PEDV) causes acute diarrhea, dehydration and death in piglets, resulting in significant economic losses in the pig industry. It is crucial to identify the pathogenesis and mechanism between host–PEDV interactions. In our study, we performed transcriptomic and metabolomic analyses in PEDV-infected Large White (LW) pigs. PEDV infection caused blunted and fused intestinal villi, necrosis of the intestinal mucosal epithelial cells and atrophy of intestinal glands. Transcriptomic and metabolomic analyses revealed 692 differentially expressed genes and 1485 differential metabolites, respectively. Among them, differentially expressed genes were enriched in virion assembly, lipoprotein metabolic process and PPAR signaling pathway. Differential metabolites were enriched in primary bile acid biosynthesis and lipoic acid metabolism. An integrated analysis of the transcriptome and metabolome revealed that differentially expressed genes and metabolites were co-enriched in steroid hormone biosynthesis and bile secretion. In addition, key metabolites Dehydroepiandrosterone (DHEA) and Estriol in steroid hormone biosynthesis both inhibited PEDV infection and alleviated the excessive inflammatory response in vitro. Collectively, our study constructed a multi-omics landscape of PEDV infection in LW pigs, providing potential targets for developing metabolic-targeted antiviral interventions.

Dietary fiber has proven beneficial for improving gastrointestinal function, its role in the small intestine has received comparatively less attention. In this study, ten Erhualian pigs (40 ± 0.86 kg) were randomly assigned to two groups: a basal diet and a 7% wheat bran-supplemented diet, respectively. Using 16S rDNA sequencing and LC-MS-based untargeted metabolomics, we observed significant shifts in small intestinal microbiota and metabolome. Five genera (Terrisporobacter, Howardella, Romboutsia, Cellulosilyticum, and Intestinibacter) showed a significant increase in abundance in pigs fed the high-fiber diet. In addition, 155 differential metabolites were identified between the two groups. Functional enrichment analysis revealed that these metabolites were particularly enriched in pathways of carbohydrate utilization and tryptophan catabolism. Correlation analysis revealed significant associations between specific microbial genera and bile acids including lithocholic acid and 23-Norcholic acid. These findings indicate that a high-fiber diet may promote tryptophan metabolism by genera such as Clostridium_sensu_stricto_1, Terrisporobacter, and Romboutsia, facilitating intestinal function and health. Overall, our findings provide new insights into the effects of dietary fiber on the microbial community and metabolome in the small intestine, and highlight the potential of certain bacterial genera as beneficial microbiota for promoting small intestinal health.

Fumonisin B1 (FB1) is a prevalent mycotoxin in moldy grains and feeds, highly toxic to livestock and compromising product quality while threatening food safety. Poultry exhibit low susceptibility to FB1, but the underlying tolerance mechanisms remain unclear. Traditional 3D chicken intestinal organoid models cannot simulate direct interaction between the epithelial monolayer and FB1, limiting the study of FB1–chicken intestinal crosstalk. Here, we established a 2D chicken intestinal organoid monolayer model, derived from intestinal crypts of 18-day-old specific pathogen-free chicken embryos, to systematically explore poultry’s resistance mechanisms against FB1. Using this model, we compared FB1-induced effects with those in a porcine intestinal epithelial cell model. Results showed that FB1 exposure did not reduce transepithelial electrical resistance, induce abnormal expression of tight junction genes, or cause significant fluctuations in inflammatory factor levels in chicken intestinal organoid monolayers. Mechanistically, FB1 enhances chicken intestinal stem cell function by activating the Wnt/β-catenin pathway, thereby promoting epithelial regeneration and renewal to increase FB1 resistance and decrease toxin sensitivity in chickens. This study reveals a strategy for enhancing FB1 tolerance in poultry by promoting intestinal stem cell function, providing a new perspective for developing mycotoxin prevention and control strategies.

Porcine epidemic diarrhea virus (PEDV) is a primary pathogen responsible for viral diarrhea in swine. The identification of host resistance genes and key regulatory elements represents a critical prerequisite for developing novel control strategies. Krüppel-like factor 4 (KLF4), a multi-functional transcription factor, is known to regulate pathogenic infections; however, its specific roles in PEDV infection remain largely undefined. In this study, we found that KLF4 expression was upregulated following PEDV infection. Next, we constructed KLF4 knockout and overexpression cells and infected them with PEDV. The results show that viral RNA and protein expression levels and infectious viral titers were significantly enhanced in PEDV-infected KLF4 knockout cells compared to infected wild-type cells. In contrast, PEDV infection levels were significantly decreased in KLF4 overexpression cells relative to control cells. Transcriptomic analysis reveals that KLF4 significantly influences the expression of genes involved in key signaling pathways, including PI3K/Akt and MAPK. Overall, our findings elucidate the functional roles and underlying mechanisms of KLF4 during PEDV infection, offering valuable molecular targets for PEDV prevention and control.

Porcine circovirus type 2 (PCV2) is an important pathogen that leads to great economic losses to the swine industry. Paeoniflorin (PF), a novel plant extract, has been reported to have antiviral properties. However, the role of paeoniflorin in regulating PCV2 replication remains unclear. Here, we used the CCK8 assay to demonstrate that PF within safe concentrations (0–275 mM) significantly inhibits PCV2 replication in a dose-dependent manner in porcine kidney cells. Subsequently, comparative transcriptome and functional verification revealed that PF probably inherits PCV2 replication via targeting AKT/mTOR signaling. Further experimental data show that the AKT/mTOR signaling pathway is highly relevant to autophagy. Thus, experimental data from Western blot, qPCR, and the indirect immunofluorescence test indicate that PF inhibits PCV2 replication by inhibiting autophagy by targeting the AKT/mTOR signaling pathway. Together, our results provide insight into the mechanism of paeoniflorin in regulating PCV2 replication and offer new ideas for the treatment of PCV2 infection in pigs.

Porcine circovirus type 2 (PCV2) is the main pathogen causing post-weaning multisystemic wasting syndrome (PMWS), which mainly targets the body’s immune system and poses a serious threat to the global pig industry. 5-Azacytidine is a potent inhibitor of DNA methylation, which can participate in many important physiological and pathological processes, including virus-related processes, by inhibiting gene expression. However, the impact of 5-Aza on PCV2 replication in cells is not yet clear. We explored the impact of 5-Aza on PCV2 infection utilizing PK15 cells as a cellular model. Our objective was to gain insights that could potentially offer novel therapeutic strategies for PCV2. Our results showed that 5-Aza significantly enhanced the infectivity of PCV2 in PK15 cells. Transcriptome analysis revealed that PCV2 infection activated various immune-related signaling pathways. 5-Aza may activate the MAPK signaling pathway to exacerbate PCV2 infection and upregulate the expression of inflammatory and apoptotic factors.

Pigs can be colonized with Salmonella enterica and become established carriers. However, the mechanisms of the host’s response to Salmonella enterica infection are largely unclear. This study was constructed with the Salmonella enterica infection model in vitro using porcine intestinal epithelial cells (IPEC-J2). Transcriptome profiling of IPEC-J2 cells was carried out to characterize the effect of Salmonella enterica infection and lipopolysaccharide (LPS) treatment, in which LPS-induced inflammation was a positive control. At first, Salmonella enterica infection increased the cell apoptosis rate and induced an inflammation response in IPEC-J2. Then, the up-regulated genes were enriched in metabolic pathways, such as those for bile secretion and mineral absorption, while down-regulated genes were enriched in immune-related pathways, such as the Toll-like receptor signaling and p53 signaling pathways. Moreover, we found 368 up-regulated genes and 101 down-regulated genes in common. Then, an integrative analysis of the transcriptomic profile under Salmonella enterica infection and LPS treatment was conducted, and eight up-regulated genes and one down-regulated gene were detected. Among them, AQP8 is one critical gene of the bile secretion pathway, and its mRNA and protein expression were increased significantly under Salmonella enterica infection and LPS treatment. Thus, the AQP8 gene and bile secretion pathway may be important in IPEC-J2 cells under Salmonella enterica infection or LPS treatment.

The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing annually, and emerging evidence suggests that the gut microbiota plays a causative role in the development of NAFLD. However, the role of gut microbiota in the development of NAFLD remains unclear and warrants further investigation. Thus, C57BL/6J mice were fed a high-fat diet (HFD), and we found that the HFD significantly induced obesity and increased the accumulation of intrahepatic lipids, along with alterations in serum biochemical parameters. Moreover, it was observed that the HFD also impaired gut barrier integrity. It was revealed via 16S rRNA gene sequencing that the HFD increased gut microbial diversity, which enriched Colidextribacter, Lachnospiraceae-NK4A136-group, Acetatifactor, and Erysipelatoclostridium. Meanwhile, it reduced the abundance of Faecalibaculum, Muribaculaceae, and Coriobacteriaceae-UCG-002. The predicted metabolic pathways suggest that HFD enhances the chemotaxis and functional activity of gut microbiota pathways associated with flagellar assembly, while also increasing the risk of intestinal pathogen colonization and inflammation. And the phosphotransferase system, streptomycin biosynthesis, and starch/sucrose metabolism exhibited decreases. These findings reveal the composition and predictive functions of the intestinal microbiome in NAFLD, further corroborating the association between gut microbiota and NAFLD while providing novel insights into its potential application in gut microbiome research for NAFLD patients.