Effect of microrNA-122-5p on neuronal injury induced by hypoxia-reoxygenation
LIU Xiaoyan
LIU Yuanyuan
LUO Nan
Abstract：Objective To investigate the effect of miR-122-5p targeting the Toll-like receptor 4(TLR4)/myeloid differentiation factor 88(MyD88)/NF-κB pathway on H/R-induced neuronal injury.Methods Neuronal cell line HT22 was randomly divided into control group,model group,miRNA negative control group,miR-122-5p mimics group,miR-122-5p mimics+empty vector group,miR-122-5p mimics+TLR4 group,small interfering RNA(siRNA)negative control group,and TLR4 siRNA group(n=6).Except for the control group,the cells in the other groups were subjected to H/R treatment and corresponding plasmid transfection.qRT-PCR was used to detect the mRNA expression of miR-122-5p and TLR4 in HT22 cells.ELISA was utilized to measure the levels of inflammatory factors and oxidative stress factors.Results Compared with the control group,the model group showed significantly decreased levels of miR-122-5p,cell viability,and SOD activity,while obviously increased TLR4 mRNA level,apoptotic rate,lactate dehydrogenase(LDH)activity,and MDA,IL-6 and IL-18 levels(P<0.05).Treatment of miR-122-5p mimic resulted in significantly elevated levels of miR-122-5p,cell viability,and SOD activity,whereas reduced TLR4 mRNA level,apoptotic rate,LDH activity,and MDA,IL-6 and IL-18 levels when compared with the treatment of miRNA negative control(P<0.05).Compared with the miR-122-5p mimic+empty vector group,the miR-122-5p mimic+TLR4 group demonstrated significantly increased TLR4 mRNA expression,apoptotic rate,and MDA,IL-6,and IL-18 levels,while decreased cell viability and SOD activity(P<0.05).Pearson correlation analysis revealed that IL-6 level and IL-18 were negatively correlated with SOD activity(r=-0.932,P<0.01;r=-0.922,P<0.01),and positively with MDA content and LDH activity(r=0.931,r=0.819,P<0.01;r=0.935,r=0.829,P<0.01).Compared with the miR-122-5p mimic+empty vector group,the miR-122-5p mimic+TLR4 group showed significantly enhanced levels of pathway-related proteins and decreased Bcl-2 protein level(P<0.05).Compared with the siRNA negative control group,the TLR4 siRNA group exhibited significantly elevated cell viability,SOD activity,and Bcl-2 protein level,while reduced apoptotic rate,LDH activity,MDA content,inflammatory factor levels,pathway-related protein expression levels,and cleaved Caspase-3 level(P<0.05).Conclusion Expression of miR-122-5p is significantly down-regulated in H/R-induced HT22 cells.Its overexpression enhances the antioxidant capacity and viability and inhibits cell apoptosis and inflammatory response in HT22 cells by targeting the TLR4/MyD88/NF-κB pathway.
Keywords：micrornashypoxiabrainneuronsToll-like receptorsmyeloid differentiation factor 88
Publication Date：2026-01-15
Online Publishing Date：2026-01-16(First online date of this platform, not the publication date of the document)
Pages：6( 113-118 )