姜黄素调节TLR4/MyD88/NF‑κB信号通路对细菌性阴道炎大鼠炎症反应和阴道菌群的影响

Impacts of curcumin on inflammatory response and vaginal flora in rats with bacterial vaginitis by regulating TLR4/MyD88/NF‑kappaB signaling pathway

目的:探究姜黄素(CUR)调节TLR4/MyD88/NF-κB信号通路对细菌性阴道炎(BV)大鼠炎症反应和阴道菌群的影响。方法:随机把SD大鼠分为对照(Ctrl)组、BV组,低、高剂量CUR(L-CUR、H-CUR)组、TLR4抑制剂组,采用加德纳氏菌(Gardnerella vaginalis)、大肠埃希菌(Escherichia coli)混合细菌悬液阴道注入法建立BV模型(Ctrl组除外);Diff-Quik染色检测阴道分泌物中细胞构成变化;HE染色观察阴道组织病理学变化;ELISA检测阴道分泌物中炎性因子表达情况;高通量测序分析阴道菌群变化[Shannon指数(多样性)、Chao指数(丰富度)及门、属水平变化);Western Blot检测阴道组织中TLR4/MyD88/NF-κB信号通路相关蛋白表达情况。结果:与Ctrl组比较,BV组大鼠阴道分泌物中阴道上皮细胞较少,可见大量白细胞,同时IL-10、TNF-α、IL-1β表达增加(P<0.05);阴道组织发生明显病理改变,阴道壁增厚,可见明显充血水肿、炎性细胞浸润,大量坏死组织脱落;阴道菌群Shannon指数、Chao指数增加(P<0.05);厚壁菌门(Firmicutes)、乳杆菌属(Lactobacillus)减少,放线菌门(Actinobacteria)、变形菌门(Proteobacteria)、Gardnerella vaginalis、Escherichia coli增加(P<0.05);阴道组织中TLR4、MyD88、NF-κB蛋白表达均增加(P<0.05);经L-CUR、H-CUR、TLR4抑制剂干预后上述情况均好转,且H-CUR、TLR4抑制剂作用效果更佳。结论:CUR能够减轻BV大鼠阴道炎症反应,调节其阴道菌群,可能通过抑制TLR4/MyD88/NF-κB信号通路而实现。

Objective:To explore the impacts of curcumin(CUR)on inflammation and vaginal flora in rats with bacterial vaginitis(BV)by regulating TLR4/MyD88/NF-κB signaling pathway.Methods:SD rats were randomly grouped into control(Ctrl)group,BV group,low-dose and high-dose CUR(L-CUR,H-CUR)groups,and TLR4 inhibitor group.BV model was established by vaginal injection of Gardnerella vaginalis and Escherichia coli mixed bacterial suspension(except Ctrl group);Diff-Quik staining was implemented to detect the changes in cell composition in vaginal secretions;HE staining was implemented to observe the pathological changes of vaginal tissue;ELISA was imple-mented to detect the expression of inflammatory factors in vaginal secretions;high-throughput sequenc-ing was implemented to analyze vaginal flora changes(Shannon index(diversity),Chao index(rich-ness),and changes at phylum and genus levels);and Western Blot was implemented to detect the ex-pression of TLR4/MyD88/NF-κB signaling pathway-related proteins in vaginal tissue.Results:Com-pared with the Ctrl group,the vaginal epithelial cells in the vaginal secretions of the rats in the BV group were less,but a large number of leukocytes could be seen,and the expressions of IL-10,TNF-α,and IL-1βwere increased(P<0.05);obvious pathological changes occurred in the vaginal tis-sue,including vaginal wall thickening,obvious congestion and edema,inflammatory cell infiltration,and a large number of necrotic tissues fell off;Shannon index and Chao index of vaginal flora increased(P<0.05);Firmicutes and Lactobacillus decreased,Actinobacteria,Proteobacteria,Gardnerella vag-inalis,and Escherichia coli increased(P<0.05);the expressions of TLR4,MyD88,and NF-κB pro-teins in vaginal tissue increased(P<0.05);after the intervention of L-CUR,H-CUR and TLR4 inhib-itors,the above conditions were improved,and the effects of H-CUR and TLR4 inhibitors were bet-ter.Conclusion:CUR can reduce vaginal inflammation and regulate vaginal flora in BV rats,which may be achieved by inhibiting TLR4/MyD88/NF-κB signaling pathway.