A 10-Day-Old Murine Model of Coxsackievirus A6 Infection for the Evaluation of Vaccines and Antiviral Drugs.

Coxsackievirus A6 (CVA6) is recognized as a major enterovirus type that can cause severe hand, foot, and mouth disease and spread widely among children. Vaccines and antiviral drugs may be developed more effectively based on a stable and easy-to-operate CVA6 mouse infection model. In this study, a wild CVA6-W strain was sub-cultured in newborn mice of different ages (in days), for adaptation. Therefore, a CVA6-A mouse-adapted strain capable of stably infecting the mice was generated, and a fatal model was built. As the result indicated, CVA6-A could infect the 10-day-old mice to generate higher levels of IFN-γ, IL-6, and IL-10. The mice infected with CVA6-A were treated with IFN-α1b at a higher dose, with complete protection. Based on this strain, an animal model with active immunization was built to evaluate antiviral protection by active immunization. The three-day-old mice were pre-immunized with inactivated CVA6 thereby generating IgM and IgG antibodies within 7 days that enabled complete protection of the pre-immunized mice following the CVA6 virus challenge. There were eight mutations in the genome of CVA6-A than in that of CVA6-W, possibly attributed to the virulence of CVA6 in mice. Briefly, the CVA6 infection model of the 10-day-old mice built herein, may serve as an applicable preclinical evaluation model for CVA6 antiviral drugs and vaccine study.

The relationship between liver-kidney impairment and viral load after nephropathogenic infectious bronchitis virus infection in embryonic chickens.

To examine the relationship of impairments of the liver and kidney with viral load after nephropathogenic infectious bronchitis virus (NIBV) infection in embryonic chickens, 120 specific-pathogen-free Leghorn embryonated chicken eggs were randomly divided into two groups (infected and control), with three replicates per group and 20 eggs in each replicate. The eggs in the infected and control groups were challenged with 0.2 mL of 105.5 ELD50 NIBV and sterile saline solution, respectively. The embryonic chickens' plasma and liver and kidney tissues were collected at 1, 3, and 5 days post-inoculation (dpi), the liver and kidney functional parameters were quantified, and the tissue viral loads were determined with real-time PCR. The results showed that plasma potassium, sodium, chlorine, magnesium, calcium, and phosphorus levels were increased. The infected group exhibited significantly higher plasma uric acid, blood urea nitrogen, and creatinine levels than the control group at 3 dpi. The plasma concentrations of aspartate aminotransferase and alanine aminotransferase were significantly increased in the infected group. The total protein, albumin, and globulin levels in the infected group were significantly lower than those in the control group. The liver-kidney viral load in the infected group peaked at 3 dpi, at which time the kidney viral load was significantly higher than that of the liver. Our results indicated that NIBV infection caused liver and kidney damage in the embryonic chickens, and the results also demonstrated that the liver and kidney damage was strongly related to the tissue viral load following NIBV infection in embryonic chickens.

Dysregulated expression of microRNAs and mRNAs in pulmonary artery remodeling in ascites syndrome in broiler chickens.

Ascites syndrome (AS), also known as pulmonary artery hypertension, remains a challenging disease that severely affects both humans and broiler chickens. Pulmonary artery remodeling presents a key step in the development of AS. In this study, we obtained pulmonary artery tissues from broilers with and without AS to perform miRNA sequencing analysis, miRNA-mRNA association analysis and pathological examinations. 29 significantly differentially expressed miRNAs were found both in known and novel miRNAs with 18 up-regulated and 11 down-regulated miRNAs. Their predicted potential targets were involved in a wide range of functional clusters as indicated via GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analyses. The upregulation of miR-155, miR-23b-3p, miR-146b-5p and miR-146b-3p were found closely associated with the pathogenesis of pulmonary artery remodeling in AS progression. The association analysis for the miRNAs-mRNAs showed that these 29 significantly differentially expressed miRNAs regulate 162 differentially expressed target genes. Among them, 20 miRNAs correlated with 18 predicted target genes that appear to be involved in pulmonary artery remodeling, mainly in three broad physiological processes: the hypoxia sensing response (HIF1α, NHE1, STAT5 and STAT3), endothelial permeability dysfunction (CD44, TRAF2, CDK2AP1, LZTFL1, JAZF1, PEBP1, LRP1B, RPS14 and THBS2) and inflammation (MEOX2, STAT5, STAT3, IRF8, MAP3K8, IL-1BETA and TNFRSF1B). Pathological pulmonary artery remodeling in the AS broilers was consistently observed in the present study. Taken together, the current analysis further illuminates the molecular mechanism of pulmonary artery remodeling underlying AS progression.

Transcriptome Analysis and Gene Identification in the Pulmonary Artery of Broilers with Ascites Syndrome.

BACKGROUND: Pulmonary arterial hypertension, also known as Ascites syndrome (AS), remains a clinically challenging disease with a large impact on both humans and broiler chickens. Pulmonary arterial remodeling presents a key step in the development of AS. The precise molecular mechanism of pulmonary artery remodeling regulating AS progression remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: We obtained pulmonary arteries from two positive AS and two normal broilers for RNA sequencing (RNA-seq) analysis and pathological observation. RNA-seq analysis revealed a total of 895 significantly differentially expressed genes (DEGs) with 437 up-regulated and 458 down-regulated genes, which were significantly enriched to 12 GO (Gene Ontology) terms and 4 KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways (Padj<0.05) regulating pulmonary artery remodeling and consequently occurrence of AS. These GO terms and pathways include ribosome, Jak-STAT and NOD-like receptor signaling pathways which regulate pulmonary artery remodeling through vascular smooth cell proliferation, inflammation and vascular smooth cell proliferation together. Some notable DEGs within these pathways included downregulation of genes like RPL 5, 7, 8, 9, 14; upregulation of genes such as IL-6, K60, STAT3, STAT5 Pim1 and SOCS3; IKKα, IkB, P38, five cytokines IL-6, IL8, IL-1ß, IL-18, and MIP-1ß. Six important regulators of pulmonary artery vascular remodeling and construction like CYP1B1, ALDH7A1, MYLK, CAMK4, BMP7 and INOS were upregulated in the pulmonary artery of AS broilers. The pathology results showed that the pulmonary artery had remodeled and become thicker in the disease group. CONCLUSIONS/SIGNIFICANCE: Our present data suggested some specific components of the complex molecular circuitry regulating pulmonary arterial remodeling underlying AS progression in broilers. We revealed some valuable candidate genes and pathways that involved in pulmonary artery remodeling further contributing to the AS progression.

Prokaryotic expression of the chicken xanthine oxidase (XOD) subunit and its localization in liver and kidney.

Xanthine oxidase (XOD) is the members of the molybdenum hydroxylase flavoprotein family and it plays a vital role in the body's purine catabolism. In this study, we cloned the XOD 37kDa subunit protein by using RT-PCR and pMD-18-T clone vector based on the total RNA extracted from chicken liver. The cloning XOD subunit protein gene was ligated into the pET-32a to construct the recombinant plasmid pET-XOD. After the pET-XOD expression vector was transformed into host cells Rosetta (DE3), the recombinant XOD subunit proteins (54.8kDa) were successfully induced by isopropy1 ß-d-thiogalactoside (IPTG). Rabbit antiserums were produced by using the purification of the recombinant XOD subunit protein as antigen. The titer of the antiserum was more than 1:102,400 determined by using ELISA. The result of Western blot demonstrated that the antiserum could specifically recognize the chicken liver XOD. Immunohistochemistry and immunofluorescence showed that the XOD mainly presented in the cytoplasm of chicken hepatocytes and proximal tubular epithelial cells. Our results indicated that the XOD subunit protein polyclonal antibody prepared by this method could be used for the further researches of the biological function of the XOD in the chicken.

Elevated level of renal xanthine oxidase mRNA transcription after nephropathogenic infectious bronchitis virus infection in growing layers.

To assess relationships between xanthine oxidase (XOD) and nephropathogenic infectious bronchitis virus (NIBV) infection, 240 growing layers (35 days old) were randomly divided into two groups (infected and control) of 120 chickens each. Each chicken in the control and infected group was intranasally inoculated with 0.2 mL sterile physiological saline and virus, respectively, after which serum antioxidant parameters and renal XOD mRNA expression in growing layers were evaluated at 8, 15 and 22 days post-inoculation (dpi). The results showed that serum glutathione peroxidase and superoxide dismutase activities in the infected group were significantly lower than in the control group at 8 and 15 dpi (p < 0.01), while serum malondialdehyde concentrations were significantly higher (p < 0.01). The serum uric acid was significantly higher than that of the control group at 15 dpi (p < 0.01). In addition, the kidney mRNA transcript level and serum activity of XOD in the infected group was significantly higher than that of the control group at 8, 15 and 22 dpi (p < 0.05). The results indicated that NIBV infection could cause the increases of renal XOD gene transcription and serum XOD activity, leading to hyperuricemia and reduction of antioxidants in the body.