鸭LMO4的克隆及其在肠炎沙门菌感染输卵管上皮细胞中对NF-κB通路的调控作用OA

This study aimed to explore the role of the duck LMO4(duck LIM domain only 4,duLMO4)in resistance to SalmonellaEnteritidis(SE)infection.The duLMO4 gene was cloned by PCR and a phyloge-netic tree was constructed.The expression of duLMO4 in different duck tissues was detected by RT-qPCR.Using the duck oviduct epithelial cells(DOECs)model,combined with gene overexpression,interference and ΔSspH2/C-ΔSspH2 SE infection assays,the expression levels of inflammatory factors such as NF-κB1,IL-6 and IL-1β were detected.Phylogenetic tree showed that it had the highest homology with the wild goose(99.39％).The duLMO4 gene was expressed in all seven tissues:heart,liver,spleen,lung,kid-ney,duodenum and oviduct epithelium,with the highest mRNA expression level observed in the oviduct epithelium.Overexpression of duLMO4 gene significantly upregulated TNF-α,NF-κB1,IL-6 and IL-1β mRNA expression(increased by 43.8％,78.2％,179.9％and 108.6％,P＜0.05)and NF-κB1 and IL-1β protein levels(increased by 47.2％and 79.7％,P＜0.05),while interference of duLMO4 gene significantly inhib-ited TNF-α,NF-κB1,IL-6 and IL-1β mRNA expression(decreased by 78.8％,66.0％,83.7％,and 91.4％,P＜0.05)and NF-κB1 and IL-1β protein levels(decreased by 64.8％and 77.9％,P＜0.05).After SE infection,compared with the wild type,the expression of LMO4 was significantly reduced by SspH2 deletion(de-creased by 92％,P＜0.05),while LMO4 expression was significantly elevated in the complementation strain C-ΔSspH2(increased by 1.29-fold,P＜0.01).In summary,the interference with duLMO4 likely reg-ulates inflammatory response by inhibiting the expression of inflammatory factor IL-1β downstream of the NF-κB pathway,and SspH2 acts as an important effector molecule of SE to modulate host inflammatory responses.