趾腿病鸵鸟主要器官的组织病理学及骨免疫相关基因在骨-免疫器官中表达研究OA

[Objective]This study aimed to investigate the histopathological changes in major organs and the expression of bone immune-related genes in the tarsal joint and immune organs of ostrich with toe and leg disease,thereby providing a theoretical basis for elucidating the pathogenesis and prevention of os-trich with toe and leg disease.[Method]Healthy and diseased male ostrich chicks were used as re-search subjects.The histopathological changes of clinical characteristic parts(tarsal joints,muscles),immune organs(spleen,thymus,bursa of Fabricius,Hadrian's gland),visceral organs(heart,liver,lungs,kidneys),and intestines(duodenum,jejunum,ileum,cecum,colon and rectum)of ostriches were studied by gross dissection and histopathology;transcriptome analysis was conducted on tarsal joint cartilage to screen for differentially expressed bone immunity-related genes,such as IL-1R2,MMP7,MHC Ⅱ,ATF3,CSF3R,LAPTM4B,LTA4H,and MLKL,followed by qPCR validation;the expression patterns of these eight bone immune-related genes in the tarsal joint and immune organs were studied.[Result]① Clinical and gross anatomical observations showed blurred cartilage structure in the tarsal joint of affected ostriches,with yellow fluid seeps out from the joint section.② Histopathological exami-nation revealed decreased and necrosis chondrocytes in the tarsal joint,accompanied by numerous empty cartilage pits and muscle fiber atrophy.Increased necrotic cells were observed in the spleen and thymus,while lymphocyte numbers were reduced in the bursa of Fabricius.The heart showed fatty degeneration of cardiomyocytes.The liver showed central venous congestion.The lungs presented increased interstitial tis-sue,thickened alveolar walls,and inflammatory cell infiltration within the alveolar interstitium.No sig-nificant pathological changes were observed in the kidneys.Apart from a decrease in goblet cells in the je-junum,other intestinal segments showed no notable alterations.③ Transcriptome analysis identified 29 differentially expressed genes(DEGs)compared to the ostrich reference genome.GO analysis revealed that these DEGs were enriched in biological processes such as primary metabolism and immune system processes.KEGG pathway analysis revealed that several pathways were associated with immunity,par-ticularly those related to T-cell proliferation and activation.④ The qPCR results indicated that the eight bone immune-related genes were expressed in the tarsal joints and immune organs of healthy ostriches,and were upregulated in the tarsal cartilage of diseased ostriches.IL-1R2,MHC Ⅱ,ATF3,CSF3R,and LAPTM4B were significantly upregulated(P<0.05)in both the thymus and bursa of Fabri-cius.MMP7 expression was significantly decreased(P<0.01)in the spleen and significantly increased(P<0.05)in the bursa of Fabricius.[Conclusion]In addition to joint lesions,ostriches with toe and leg disease exhibited multiple organ lesions,with the thymus,spleen,and bursa of Fabricius being most severely affected.GO and KEGG results indicated the involvement of immune system processes and related pathways.Bone immunity-related genes showed significant expression changes in the tarsal joint and immune organs of affected ostriches.These findings suggest that the eight bone immunity-related genes are involved in the pathogenesis of tarsal joint and immune organ damage in ostriches with toe and leg disease.