Inhibition of AKR1B1 alleviates sepsis-induced acute lung injury in rats by regulating macrophage polarization
Objective To explore the effect of inhibition of aldo-ketone reductase 1 member B1(AKR1B1)on sepsis-induced acute lung injury(ALI)in rats and the underlying mechanism.Methods A total of 60 Sprague-Dawley(SD)rats were randomly assigned into control group,model group,low-dose group,and high-dose group,with 15 rats in each group.Except for the control group,rats in the other three groups were used to establish sepsis-induced ALI model by cecal ligation and puncture.Rats in the low-dose and high-dose groups were given epalrestat by gavage at 50mg/kg and 100mg/kg,respectively,once a day for 6 consecutive weeks.After 6 weeks,immunohistochemical staining was used to detect the expression of AKR1B1 in the lung tissue of the control and model groups.Enzyme-linked immunosorbent assay(ELISA)was used to detect the levels of inflammatory cytokines tumor necrosis factor α(TNF-α),interleukin 1β(IL-1β)and interleukin 6(IL-6)in bronchoalveolar lavage fluid(BALF)and serum.The wet weight(WW)and dry weight(DW)of the left lung tissue were weighed,and the WW/DW ratio was calculated.Hematoxylin-eosin(HE)staining was used to observe the pathological morphologic changes in lung tissue.The terminal deoxynucleotidyl transferase dUTP nick end-labeling(TUNEL)staining was used to detect the apoptosis of lung tissue cells.Flow cytometry was used to detect the expressions of M1(F4/80+CD86+)and M2(F4/80+CD206+)macrophages in rat bronchoalveolar lavage fluid(BALF).Real-time fluorescence quantitative PCR was used to detect the expression levels of M1 and M2 markers in rat lung tissue.Results The expression of AKR1B1 in the lung tissue of the model group was significantly higher than that of the control group(P＜0.05).Compared with those of the model group,TNF-α,IL-1β and IL-6 levels in serum and BALF were significantly lower in the low-dose and high-dose groups after epalrestat treatment(P＜0.05).The WW/DW ratio of right lung tissue was lower in the low-dose and high-dose groups than that of control group(P＜0.05).Low-dose and high-dose epalrestat treatment significantly alleviated pathological lesions in the lungs,reduced inflammatory cell infiltration and TUNEL-positive cell ratio than those of control group(P＜0.05).The positive expression rate of F4/80+CD86+in BALF significantly decreased,and the positive expression rate of F4/80+CD206+in BALF significantly increased in the low-dose and high-dose groups(P＜0.05).The mRNA expressions of M1 markers TNF-α,inducible nitric oxide synthase(iNOS)and IL-6 in lung tissue were significantly down-regulated(P＜0.05),while those of M2 markers TGF-β,arginase-1(Arg-1)and IL-10 were up-regulated by low-dose and high-dose epalrestat treatment(P＜0.05).Conclusion AKR1B1 is overexpressed in lung tissue of sepsis-induced ALI rats.Inhibition of AKR1B1 alleviates lung injury in rats by inhibiting the transformation of M1 macrophages to M2 type.
万方数据
维普
