TLR4通过自噬和氧化应激对胃溃疡小鼠炎症反应的调控机制OA

Objective To investigate the effects of Toll-like receptor 4(TLR4)inhibition on autophagy and oxida-tive stress,as well as its regulatory role and mechanism in the inflammatory response in a mouse model of gastric ul-cer.Methods Sixty adult male Kunming mice were equally divided into five groups:control group,model group,model+TLR4-IN-C34 group,model+TLR4-IN-C34+3-MA group,and model+TLR4-IN-C34+H₂O₂ group.Except for the control group,all groups were administered 40 mg/kg indomethacin via gavage.Treatment groups received injections every three days,and all groups were treated for 30 days.Mice were euthanized by cervical dislocation,and gastric tissues were collected.Gastric ulcer scores were assessed,and pathological changes were evaluated via HE staining and scoring.Serum levels of interleukin-1β(IL-1β),IL-6,tumor necrosis factor-α(TNF-α),ad-vanced oxidation protein products(AOPP),and prostaglandin E2(PGE2),as well as gastric tissue levels of malo-ndialdehyde(MDA),superoxide dismutase(SOD),and reduced glutathione(GSH),were measured using ELISA.Western blot analysis was performed to detect the expression of TLR4,microtubule-associated protein 1 light chain 3-Ⅰ(LC3-Ⅰ),LC3-Ⅱ,autophagy-related protein 5(Atg5),Beclin-1,nuclear factor erythroid 2-re-lated factor 2(Nrf2),heme oxygenase-1(HO-1),and NAD(P)H quinone dehydrogenase 1(NQO1)in gastric tis-sues.Immunofluorescence staining was used to assess LC3-Ⅱ fluorescence intensity in gastric tissues.Results Compared with the control group,the model group exhibited upregulation of ulcer scores,HE staining scores,TLR4,IL-1β,IL-6,TNF-α,and AOPP levels,and downregulation of LC3-Ⅱ fluorescence intensity,PGE2 lev-els,Atg5,Beclin-1,nuclear Nrf2,HO-1,NQO1 levels,and the LC3-Ⅱ/Ⅰ ratio(all P<0.05).Compared with the model group,the model+TLR4-IN-C34 group showed downregulation of ulcer scores,HE staining scores,TLR4,IL-1β,IL-6,TNF-α,and AOPP levels,and upregulation of LC3-Ⅱ fluorescence intensity,PGE2 levels,Atg5,Beclin-1,nuclear Nrf2,HO-1,NQO1 levels,and the LC3-Ⅱ/Ⅰ ratio(all P<0.05).Compared with the model+TLR4-IN-C34 group,the model+TLR4-IN-C34+3-MA group exhibited upregulation of ulcer scores,HE staining scores,IL-1β,IL-6,TNF-α,and AOPP levels,and downregulation of LC3-Ⅱ fluorescence intensity,PGE2 levels,Atg5,Beclin-1,and the LC3-Ⅱ/Ⅰ ratio(all P<0.05).Compared with the model+TLR4-IN-C34 group,the model+TLR4-IN-C34+H₂O₂ group showed upregulation of ulcer scores,HE staining scores,IL-1β,IL-6,TNF-α,and AOPP levels,and downregulation of PGE2 levels and nuclear Nrf2,HO-1,and NQO1 levels(all P<0.05).Conclusion Inhibition of TLR4 ameliorates gastric ulcer symptoms and suppresses the inflammatory response in mice by upregulating autophagy and reducing oxidative stress.