Baicalin attenuated Mycoplasma gallisepticum‐induced immune impairment in chicken bursa of fabricius through modulation of autophagy and inhibited inflammation and apoptosis

Abstract

BACKGROUNDMycoplasma gallisepticum (MG) is the primary etiologic agent of chronic respiratory disease in poultry. However, the mechanism underlying MG‐induced immune dysregulation in chicken is still elusive. Baicalin shows excellent anti‐bacterial, anti‐inflammatory, anti‐carcinogenic and anti‐viral properties. In the present study, the preventive effects of baicalin against immune impairment in chicken bursa of fabricius (BF) were studied in an MG infection model.RESULTSHistopathological examination showed increased inflammatory cell infiltrations and fragmented nuclei in the model group. Ultrastructural analysis revealed the phenomenon of apoptosis in bursal cells, along with the deformation of mitochondrial membrane and swollen mitochondria in the model group. However, these abnormal morphological changes were partially alleviated by baicalin. Meanwhile, baicalin treatment attenuated the level of proinflammatory cytokines, and suppressed nuclear factor‐kappa B expression at both protein and mRNA level. Terminal deoxynucleotidyl transferase‐mediated dUTP nick endlabeling assay showed extensive apoptosis in BF in the model group. The mRNA and protein expression levels of apoptosis‐related genes were upregulated in BF, while baicalin treatment significantly alleviated apoptosis in BF. In addition, alterations in mRNA and protein expression levels of autophagy‐related genes and mitochondrial dynamics proteins were significantly alleviated by baicalin. Moreover, baicalin treatment significantly attenuated MG‐induced decrease in CD8+ cells and reduced bacterial load in chicken BF compared to the model group.CONCLUSIONSThese results suggested that baicalin could effectively inhibit MG‐induced immune impairment and alleviate inflammatory responses and apoptosis in chicken BF. © 2020 Society of Chemical Industry

Glycyrrhizic Acid against Mycoplasma gallisepticum-Induced Inflammation and Apoptosis Through Suppressing the MAPK Pathway in Chickens

“…MG infection mainly causes CRD in chickens, causes serious inflammatory reaction and immune response through colonization on the respiratory mucosa. 29,30 MG is extremely prevalent in poultry farms around the world, especially in the developing countries. 25 Currently in the poultry industry, antibiotics are the primary and most effective way to treat CRD caused by MG. 31 Although antibiotics are effective in killing MG, discontinuation of antibiotics administration might lead to recurrence of the disease.…”

Baicalin inhibits inflammation caused by coinfection of Mycoplasma gallisepticum and Escherichia coli involving IL-17 signaling pathway

“…The lung tissue samples were homogenized for 2 min at a low frequency of 65 Hz using an automatic tissue homogenizer machine (Shanghai Jingxin Industrial Development Co., Ltd.). Total RNA was extracted using TRIzol reagent (Invitrogen Inc., Carlsbad, CA) as previously described ( Ishfaq et al., 2020b ), and the reverse transcription of cDNA was performed in accordance with the manufacturer's instructions (Takara Biomedical Technology (Beijing) Co., Ltd.). In accordance with our previous study ( Wu et al., 2019b ), 13 genes in IL-17 signaling pathway were selected for further experimental analyses, which had showed significant changes in coinfection of MG and E. coli .…”

Mucosal immune responses in the trachea after chronic infection withMycoplasma gallisepticumin unvaccinated and vaccinated mature chickens

“…The fifth row shows the merged image of the top four images in each column at Â400 and the sixth row the merged images at Â630 magnification M. gallisepticum, enabling it to survive in the tracheal tissues. Infection with M. gallisepticum has been found to cause similar signs of immune dysregulation in the bursa of Fabricius in recent studies(Ishfaq et al, 2021;Zhang et al, 2020). IFN-γ is involved in mediating CD8 +…”