Expression Studies Of IRF3 And IRF7 In TLR4 Signaling Pathway Of Rana Dybowskii Under Stress Of Aeromonas Hydrophila

In recent years,due to many factors such as disease outbreak and habitat destruction,especially the influence of pathogenic microorganisms in the environment,the global population of amphibians has been declining sharply,which has caused widespread concern.When microorganisms invade,Toll-like receptors serve as the body's pathogen associated molecular pattern could activate the innate immune response and a series of signal cascade reactions.In this study,we selected R.dybowskii,a dominant amphibian in Northeast China,as the research object,and Aeromonas hydrophila was used as the infection source,to study the effects mechanisms of Nuclear Transcription Factor IRF3 and IRF7 in TLR4 Signaling Pathway of Rana dybowskii Under Microbial Stress.In this study,HE staining was used to observe the histopathological changes of the liver after Ah infection in Rana dybowskii.and used high-throughput sequencing to obtain primers designed for IRF3 and IRF7 sequences of Rana dybowskii,and detected the liver and heart under Ah stress by fluorescent quantitative PCR.The expression of IRF3 and IRF7 mRNA in TLR4 signaling pathway was detected in liver,kidney,spleen and kidney.In order to improve the function mechanism of the TLR4 pathway in Rana dybowskii were infected by bacteria.The experimental results show:Histopathological observation of liver tissue after Ah infection,as the time prolonged(12?72 h)for Ah infection,hepatocytes degeneration,vacuolar degeneration,increased cell space,inflammatory cell infiltration gradually obvious.Real-time fluorescent PCR results show:the expression of IRF3 mRNA in the liver,heart,kidney and spleen tissues of the Rana dybowtskii TLR4 signal pathway was detected by fluorescence quantitative PCR and reached the peak at 12h.IRF7 mRNA was up-regulated in the liver,heart,kidney,and spleen,and kidney,Heart peaked at 12h,spleen at 24h,and liver peaked at 72h.In addition,the up-regulated expression of IRF3 mRNA in the kidney and spleen was significantly higher than that in the heart and liver,especially in the spleen,which was 13.7 times higher than in the control group(p?0.01);the IRF7 mRNA expression was also most pronounced in the spleen,it was 13 times(p?0.01),followed by 9 times the control group(p?0.01)in spleen.The expression in liver was the lowest 4.3 times of the control group(p?0.01).The results showed that Aeromonas hydrophila had strong pathogenicity to Rana dybowskii,and IRF3 and IRF7 participated in Innate immune response to signaling pathways.