Metabolomics Study Of Bursal Tissue Of Laying Hens By Nephropathogenic Infectious Bronchitis Virus Infection

The aim of this study was to investigate the changes of metabolites in bursal tissue of laying hens caused by nephropathogenic bronchitis virus(Nephropathogenic IBV)by gas chromatography-mass spectrometry(GC-MS).Potential biomarkers associated with the pathogenesis of Nephropathogenic IBV and study related metabolic pathways.The 240 Hy-line variety brown hens of 21 days old with similar body condition were randomly divided into the normal group(Nor)and the infected group(IBV).Each chicken in the infected group was intranasally inoculated with 0.2mL of 10~-5.55.5 median embryo infectious doses of Nephropathogenic IBV.Chickens in the control group were intranasally inoculated with 0.2 mL of sterile physiological saline.The kidney and bursal of the genus were collected when the clinical symptoms were obvious.The kidney was used for histopathological observation and the bursal was used for GC-MS research.The results are as follows:1.Histopathological observation:In the infected group,the kidney was swollen,the bleeding was severe,and deposits of pale urate was attached to the surface,which became a typical red"spotted kidney".H.E staining showed that the normal tissue of the kidney tissue was intact and the lumen of the renal tubule was clear.In the infected group,the nephron was reduced,the tissue was dissolved,the renal tubule became thick,the tubular epithelial cell nucleus was deformed,and lymphocytes infiltrated.The Nephropathogenic IBV-induced poultry gout model was successfully established.2.Metabolomics analysis:A total of 617 peaks were detected in the bursal by GC-MS technique,and 519 effective peaks were screened.Finally,75 differential abundant metabolites related to the pathogenesis of Nephropathogenic IBV chicken gout were screened from bursal tissue.Among them,there are 17 differential abundant metabolites were down-regulated(P<0.05)in the Nephropathogenic IBV model chicken bursal compared with the normal group chickens,including glutaraldehyde,2-deoxy-D-glucose,3-Methylglutaric Acid,Adenosine,Inosinic acid,Gamma-Aminobutyric acid,Tartronic acid,O-acetylserine?serine,N-Methyl-DL-alanine,Oxoproline,glutamic acid,aspartic acid,lactic acid,Ascorbate,serine,N-methyl DL-alanine,proline,glutamic acid,aspartic acid,lactic acid,ascorbic acid.And there are 58 differential abundant metabolites were up-regulated(P<0.05)in the Nephropathogenic IBV model chicken bursal,including2-Monopalmitin,N-formyl-L-methionine,threonine,Methylmalonic acid,Xylitol,Lysine,N-Carbamylglutamate,Valine,Isoleucine,Pantothenic acid,Citraconic acid,Oxamide,Lyxose,mannose,Gluconic lactone,Heptadecanoic acid O-Phosphoserine,palmitic acid,3,4-Dihydroxypyridine,stearic acid,Aminomalonic acid,Arachidonic acid,Ethanolamine,2-Deoxytetronic acid,N-Acetyl-beta-D-mannosamine,Pipecolinic acid,Glucuronic acid,Threitol?2-Methylglutaric Acid,Ribose,D-galacturonic acid,Glucosaminic acid,3-Hydroxypropionic acid,uric acid,2,4-diaminobutyric acid,2-hydroxybutanoic acid,Fructose,Threonic acid,Guanidinosuccinic acid,Glycerol,linoleic acid,3-Phenyllactic acid,N-alpha-Acetyl-L-ornithine,Pyruvic acid,glutamine,glycocyamine,linoleic acid,3-phenyl lactic acid,pyruvic acid,glutamine,thioglycolic acid,N-?-acetyl-L-ornithine.The differential metabolites found are expected to be potential biomarkers for the diagnosis of NIB.3.The metabolic pathways in laying hens after Nephropathogenic IBV infection which involve differential abundant metabolites,icluding biosynthesis of unsaturated fatty acids,metabolism of alanine,aspartic acid and glutamic acid,metabolism of linoleic acid,metabolism of arachidonic acid,glycerolipids Metabolism,aminoacyl-tRNA biosynthesis,ascorbic acid and aldehyde acid metabolism,arginine and proline metabolism,sputum metabolism,and so on.This study demonstrates that changes in immune-related metabolites and their involvement in metabolic pathways are closely related to immune tissue damage;Differential abundant metabolites were detected in glucose metabolism,fatty acid metabolism,and amino acid metabolic pathways,it is mainly manifested in fatty acid metabolism and amino acid metabolism disorder,related to the compensatory increase in energy;the increase of uric acid in the bursal tissue of the infected group may be due to the increase of XOD activity after infection with Nephropathogenic IBV which promotes the metabolism of sputum,and lays a foundation for studying the pathogenesis of Nephropathogenic IBV at the metabolic level.