硫氧还蛋白(Trx)对糖尿病视网膜病变模型鼠血清补体Clq肿瘤坏死因子相关蛋白9(CTRP9)表达的影响

Effects of thioredoxin on the expression of serum complement Clq tumor necrosis factor-related protein 9 in diabetic retinopathy rats

目的探讨硫氧还蛋白(thioredoxin,Trx)对糖尿病视网膜病变(diabetic retinopathy,DR)模型鼠血清补体Clq肿瘤坏死因子相关蛋白9(complement Clq tumor necrosis factor-related protein 9,CTRP9)表达的影响。方法 24只SPF级雄性SD大鼠分为正常对照组(NC组)12只和高脂饮食组12只,NC组以标准大鼠饲料喂养,高脂饮食组以高脂高糖饲料喂养后以一次性腹腔注射链脲佐菌素(60 mg·kg^(-1))制造DR模型,造模成功的高脂饮食组大鼠随机分为DR组(6只)和治疗组(6只)。治疗组大鼠每天腹腔注射Trx(50 mg·kg^(-1))持续1周,NC组和DR组大鼠每天给予腹腔注射同等体积的PBS。酶联免疫吸附实验检测血清CTRP9水平,免疫组织化学检测CTRP9蛋白表达水平,同时进行视网膜细胞凋亡指数与活性氧(reactive oxygen species,ROS)荧光强度分析。结果所有高脂饮食组大鼠都造模成功,高脂饮食组大鼠血清中CTRP9含量和免疫组织化学检测CTRP9表达量均低于NC组,治疗组高于DR组(均为P<0.05)。高脂饮食组大鼠的视网膜荧光强度(67.29±1.94)显著高于NC组(5.39±1.29),治疗组(34.20±5.11)低于DR组(78.11±6.33),差异均有统计学意义(均为P<0.05)。Western blot结果显示,高脂饮食组大鼠的CTRP9相对表达量低于NC组,治疗组高于DR组;高脂饮食组大鼠的PI3K相对表达量高于NC组,治疗组低于DR组(均为P<0.05)。结论 Trx可保护DR大鼠的视网膜细胞免受ROS的损伤,抑制细胞凋亡,促进CTRP9的表达,其机制可能与CTRP9改善PI3K信号通路有关。

Objective To investigate the effects of thioredoxin (Trx) on the expression of serum complement Clq tumor necrosis factor-related protein 9 (CTRP9) in diabetic retinopathy (DR) rats. Methods Totally 24 specific pathogen-free (SPF) rats were divided into normal control (NC) group and high-lipid diet group,with 12 rats in each group.The standard diet was provided to rats in NC group,and high-lipid and high-glucose diet was offered to those in high-lipid diet group.After that,Streptozotocin (STZ,60 mg·kg^-1 ) was intraperitoneally injected to establish the models,and those successfully established rat models in high-lipid diet group were randomly divided into DR group and treatment group,with 6 rats in each group.Rats in treatment group were intraperitoneally injected by Trx (50 mg·kg^-1 ) each day for one week,and those in NC group and DR group were intraperitoneally injected with PBS of the same volume.Serum CTRP9 levels were detected by enzyme-linked immunosorbent assay,and CTRP9 protein levels were determined by immunohistochemistry.Meanwhile,apoptotic index and reactive oxygen species fluorescent intensity analysis were performed on retinal cells. Results The models were successfully established for all rats in high-lipid diet group,and serum CTRP9 levels and CTRP9 protein expression levels in high-lipid diet group determined by immunohistochemistry were lower compared to NC group,and those in treatment group were higher compared to DR group (all P <0.05).Retinal fluorescence intensity of rats in high-lipid diet group (67.29±1.94) was higher than that in NC group (5.39±1.29),and that in treatment group was lower compared to DR group (34.20±5.11 vs .78.11±6.33),with significant difference (all P <0.05).According to the results of Western blot,the relative expression level of CTRP9 in the high-lipid diet group was lower than that in the NC group,and that in treatment group was higher compared to DR group;the relative expression level of PI3K in the high-lipid diet group was higher than that in the NC group,and that in treatment group was lower compared to DR group (all P <0.05). Conclusion Trx can protect retinal cells in DR rats from reactive oxygen species injuries,inhibit cell apoptosis,and promote CTRP9 expression.The mechanism may be related to PI3K signal pathway promoted by CTRP9.