藏红花素通过抑制铁死亡减轻模型大鼠视网膜缺血/再灌注损伤OA

Objective To find potential effect of crocin(Cro)to alleviate retinal ischemia-reperfusion injury(RI/RI)in rat's model.Methods Rats were divided into 6 groups(n=12):sham operation group(sham),RI/RI group(rats with RI/RI model established by intraocular perfusion),25Cro group,50Cro group(intraperitoneal injec-tion of 25 and 50 mg/kg Cro,respectively),50Cro+OSS(OSS_128167)group(intraperitoneal injection of 50 mg/kg Cro and 20 mg/kg Sirt6 inhibitor OSS),and 50Cro+Erastin group(intraperitoneal injection of 50 mg/kg Cro and 15 mg/kg ferroptosis inducer Erastin).The administration time was 30 min before RI/RI mod-eling.Rats were sacrificed 24 h after RI/RI treatment,retinal injury and cell apoptosis were evaluated by hema-toxylin-eosin(HE)staining microscopy and terminal deoxynucleotidyl transferase mediated dUTP nick end-labe-ling(TUNEL)staining.The level of reactive oxygen species(ROS),malondialdehyde(MDA),superoxide dis-mutase(SOD),reduced glutathione(GSH)and Fe2+in the retina was detected.The mRNA level of Sirt6,glu-tathione peroxides 4(Gpx4),solute carrier family 7 member 11(Slc7a11),ferritin heavy chain 1(Fth1),ferro-portin 1(Fpn1),transferrin receptor(Tfrc),interleukin-6(Il-6),tumor necrosis factor-α(Tnf-α)and cycloox-ygenase-2(Cox-2)in the retina was detected by RT-qPCR.The protein level of Sirt6,GPX4,B-cell lymphoma 2(Bcl-2),Bcl-2 associated X protein(Bax)and cleaved caspase-3 in the retina was detected by Western blot.The positive expression of Sirt6 and GPX4 in the retina was detected by immunohistochemical staining.Results Compared with sham group,the retina of rats in RI/RI group showed significant damage.The proportion of TUNEL+in the retina,the level of ROS,MDA and Fe2+,mRNA of IL-6,TNF-α,COX-2 and TFRC,and the protein level of Bax and cleaved caspase-3 were all increased(P＜0.05).The level of GSH and SOD activity,the mRNA level of Fth1,Fpn1,Gpx4,Slc7a11 and Sirt6,and the protein level of Bcl-2,GPX4 and Sirt6 were all decreased(P＜0.05).Compared with RI/RI group,the retinal damage in 25Cro group and 50Cro group was significantly alleviated,and the other indicators were significantly relieved(P＜0.05).Compared with 50Cro group,the retinal injury of rats in 50Cro+OSS group and 50Cro+Erastin group were exacerbated.The propor-tion of retinal TUNEL+,the level of ROS,MDA and Fe2+,the mRNA levels of Il-6,Tnf-α,Cox-2 and Tfrc,and the protein levels of Bax and cleaved caspase-3 all increased(P＜0.05).The levels of GSH and SOD ac-tivity,the mRNA levels of Fth1,Fpn1,Gpx4,Slc7a11 and Sirt6,and the protein level of Bcl-2,GPX4 and Sirt6 was all decreased(P＜0.05).Conclusions Crocin alleviates RI/RI in rats by inhibition of Sirt6-media-ted ferroptosis.