ABSTRACT
Objective To investigate the protective effect and mechanism of curcumin on acute lung injury in septic mice.Methods Totally 120 clean BALB/c male mice were randomly (random number) divided into 8 groups:sham group,sepsis group,curcumin control group,curcumin intervention group,negative virus-sepsis group,negative virus-curcumin intervention group,Mfn2 interference-sepsis group,and Mfn2 interference-curcumin intervention group,15 rats in each group.Mice in the sepsis and the curcumin groups were given the cecal ligation and puncture (CLP) mice in the curcumin intervention and curcumin control groups were given curcumin 200 mg/(kg·d) for 1 week,and mice in the negative virus-sepsis group and negative virus-curcumin intervention groups were established by injection of a negative adeno-associated virus in the tail vein.The Mfn2 interference-sepsis and Mfn2 interference-curcumin intervention groups were established by injecting an adeno-associated virus carrying the Mfn2 interference sequence through the tail vein.Mice were sacrificed after 24 h in each group.The degree of lung injury was examined by lung wet-to-dry weight ratio and pathological examination.The inflammatory factors of alveolar lavage fluid including TNF-α and IL-6 were detected by ELISA,the activation of caspase-3,a key molecule for apoptosis,was detected by Western blot,and apoptosis was detected by TUNEL.The data were analyzed by SPSS 22.0 software,the count data was analyzed by x2 test,and the comparison of measurement data between groups was analyzed by one-way ANOVA.Results Compared with the sham group,the wet-to-dry weight ratio of lung tissue in the sepsis group was significantly increased (71.11 ± 3.78 vs 31.11 ± 5.61,P=0.002),the histopathological score was significantly higher (P=0.006),the inflammatory factors TNF-α (P=0.001) and IL-6 (P=0.012) were dramatically increased,and the apoptosis of lung tissue and the expression of caspase-3 cleaved were also significantly increased (P=0.001).Compared with the sepsis group,the wet-to-dry weight ratio and the histopathological score of lung tissue in the curcumin-treated group was significantly lower (32.84 ± 6.15 vs 71.11 ± 3.78,P=0.004),and the inflammatory factors TNF-α(P=0.013) and IL-6 (P=0.003) were obviously decreased,and apoptosis and apoptosis-related protein caspase-3 cleaved expression were also dramatically decreased (P=0.012).After Mfn2 was down-regulated,Mfn2 interference-curcumin intervention group interfered with Mfn2.Compared with the sepsis group,the dry-to-wet weight ratio and the histopathological score of the lung tissue of the mice was not significantly decreased.Further studies found that after down-regulating Mfn2,compared with the Mfn2 interfere-sepsis group,Mfn2 interfere-curcumin intervention group had no such performance.The inflammatory factors TNF-α and IL-6 were not significantly decreased,and the apoptosis of lung tissue and the expression of apoptosis-related protein caspase-3 cleaved were not significantly reduced.Conclusion Curcumin may attenuate acute lung injury in sepsis by up-regulating the expression of Mfn2.
ABSTRACT
Objective To investigate the effects of histone deacetylase inhibitors trichostatin A (TSA) on acute lung injury in septic mice.Methods Septic mice model was induced by cecal ligation and puncture(CLP).Ninty male BALB/c mice of clean grade were randomly(random number) divided into six groups(n=15),namely sham operation group,CLP group,CLP+DMSO group,CLP+TSA 1 mg group,CLP+TSA 5 mg group,and CLP+TSA 10 mg group.TSA(1 mg/kg,5 mg/kg,10 mg/kg) was administrated 12 hours before operation by intraperitoneal injection.And mice in sham group were only treated with laparotomy without CLP,and 24 h later,all survived mice were sacrificed to obtain specimens.ELISA method was employed to detect the concentrations of TNF-α and IL-1β in BALF.The lung wet/dry ratio was calculated.Histopathology changes of lung tissues were observed under light microscope.Lung tissue cell apoptosis was detected by TUNEL method.Caspase-3,Caspase-9 and CytC were assayed by Western blotting.The survival rate of mice in each group was calculated by additional 120 mice.Data were analyzed by SPSS 23.0.Statistical analyses were performed using independent sample t-test to compare between two groups or one-way analysis of variance test to compare among muhiple groups.The survival rate of mice was analyzed by univariate analysis using log-rank test.Results The lung W/D(P=0.021),the concentrations of TNF-α(P=0.000 1)and IL-1β(P=0.000 6)in BALF,puhnonary pathological change(P=0.001 6),lung tissue cell apoptotic index(P=0.000 9),the levels of apoptosis proteins (P＜0.05) in CLP group were higher than those in sham group,while survival rate (P=0.000 1) in CLP groups was lower than that in sham group.Compared with DMSO,the TSA significantly reduced the lung W/D,the levels of TNF-α.IL-1β in BALF,pathologic changes of lung tissue,lung tissue cell apoptotic index and the levels of apoptosis proteins in septic mice(P＜0.05).The increase in survival rate (P=0.007 2) associated with TSA(10 mg/kg)administration.Conclusion TSA exerts protective effects through attenuating pro-inflammatory cytokines and lung tissue cell apoptosis in sepsis induced acute lung injury in mice.