Effect Of Curcumin On Cartilage Injury In Rats With Traumatic Arthritis By Regulating SIRT3-FoxO3 Signal Pathway

Objective: Based on the pathogenesis of traumatic arthritis(TA),the purpose of this study was to investigate the therapeutic effect of curcumin(Cur)on traumatic arthritis and the effect of curcumin on cartilage injury in rats with knee traumatic arthritis by regulating SIRT3-FoxO3 pathway.Methods: 54 4-week-old SD rats were randomly divided into five groups: A group(Control group),B group(TA group),C group(TA+Cur group),D group(TA+Cur+TRT group,SIRT3 agonist)and E group(TA+Cur+3-TYP group,SIRT3 inhibitor).The TA model of knee joint in 4 groups except Con group was established by Hulth method,and the corresponding drugs were given according to the group for 8 weeks after the establishment of the model.The cartilage tissue of knee joint of rats was taken,and the Mankin’s score was performed by toluidine blue staining and hematoxylin-eosin(HE)staining combined with the gross morphology of articular cartilage,the expressions of SIRT3,FoxO3,Bcl-2,Bax,Caspase-3,Collagen Ⅱ in cartilage tissue of knee joint were detected by Western blot,Collagen Ⅱ protein expression were detected in knee cartilage by using immunohistochemical methods,the FoxO3,Bcl-2,Bax,Caspase-3,Collagen Ⅱ gene expression levels in chondrocytes of the five group models were analyzed by reverse transcription-PCR(RT-PCR),the levels of Malondialdehyde(MDA)and Superoxide dismutase(SOD)in protein expression of rats in each group were detected by enzyme-linked immunosorbent assay(ELISA),Results:(1)Animal modeling: 50 SD rats did not die during the whole experiment,10 rats were blank control group,and the other 40 rats were successfully modeled by TA.(2)Compared with the A group,the total score of Mankin’s,the expression of Caspase-3,Bax proteins and genes,and the expression of MDA in knee cartilage increased in B group(P<0.01),while the expression of SOD activity,SIRT3,FoxO3,Bcl-2,Collagen Ⅱ protein and FoxO3,Bcl-2,Collagen Ⅱ gene expression in cartilage decreased in B group(P<0.01).Compared with the B group,the total Mankin’s score,the expression of MDA,the expression of Bax,Caspase-3 proteins and genes in knee cartilage tissue decreased in C group(P<0.01),while the expression of SOD activity,SIRT3,FoxO3,Bcl-2,Collagen Ⅱ protein and FoxO3,Bcl-2,Collagen Ⅱ gene expression in cartilage tissue increased in C group(P<0.05).Compared with C group,the total score of Mankin’s,the expression of MDA,the expression of Caspase-3 and Bax genes in knee cartilage tissue decreased in D group(P<0.05),while the expression of SOD activity,SIRT3,FoxO3,Bcl-2,Collagen Ⅱ protein and FoxO3,Bcl-2,Collagen Ⅱ gene expression in cartilage tissue increased in D group(P<0.05).Compared with C group,the total score of Mankin’s,the expression of MDA,the expression of Caspase-3,Bax proteins and Caspase-3 and Bax genes in knee cartilage tissue increased in E group(P<0.05),while the expression of SOD activity,FoxO3,Bcl-2,Collagen Ⅱ protein and FoxO3,Bcl-2,Collagen Ⅱ gene expression in cartilage tissue decreased in E group(P<0.05).(3)Collagen Ⅱ immunohistochemical staining,the whole layer chondrocytes were positive in group A,only a few chondrocytes in the deep layer were weakly positive in group B,a few chondrocytes were positive in the superficial layer and negative in the deep chondrocytes in group C,the most of the chondrocytes in the whole cartilage layer were positive in group D,the chondrocytes were rarely positive in group E.Conclusion:(1)Our study confirmed that using Hulth method established rat knee joint is a feasible method to build animal model of traumatic arthritis.(2)Curcumin can reduce cartilage injury in rats with traumatic arthritis by up-regulating SIRT3 expression and down-regulating FoxO3 acetylation level.(3)The protective effect of curcumin on apoptosis of chondrocytes was significantly inhibited by the inhibition of SIRT3-FoxO3 signal pathway by adding 3-TYP,indicating that SIRT3 is a target of curcumin in the treatment of TA.