红景天苷对糖尿病足溃疡大鼠Nrf2/Keap1信号通路及伤口愈合的影响

Effects of salidroside on the Nrf2/Keap1 signaling pathway and wound healing in rats with diabetic foot ulcer

目的探究红景天苷(Sal)对糖尿病足溃疡(DFU)大鼠核转录因子E2相关因子2/Kelch样环氧氯丙烷相关蛋白1(Nrf2/Keap1)信号通路及伤口愈合的影响。方法采用高脂高糖饲料喂养结合腹腔注射链脲佐菌素(STZ)建立糖尿病大鼠模型,并于足背部除毛剪皮至筋膜,制作面积约为3 mm×7 mm的溃疡创面建立DFU大鼠模型,随机分为DFU模型组(DFU组)、Sal低(Sal-L,0.1 g/(kg·d))、中(Sal-M,0.2 g/(kg·d))高(Sal-H,0.3 g/(kg·d))剂量组,阳性药物二甲双胍组(MET组,0.65 g/(kg·d)),另设血糖正常创面大鼠为对照组(NC组),连续灌胃2周。分别于治疗第7天、第14天后检测各组大鼠体重及空腹血糖(FBG)水平,免疫组化检测创面组织CD34表达情况,计算创面微血管密度(MVD);生物化学法测定创面组织MDA、SOD水平;免疫印迹(Western blot)检测创面组织Nrf2、Keap1蛋白表达。结果治疗第0天各组大鼠体重之间比较无统计学意义(P>0.05),各组DFU组、Sal-L组、Sal-M组、Sal-H组、MET组大鼠FBG水平均高于NC组(P<0.05);治疗第7天、第14天,与NC组比较,DFU组、Sal-L组、Sal-M组、Sal-H组、MET组大鼠体重、FBG水平、MDA含量、Keap1蛋白表达量均升高(P<0.05),创面愈合率、CD34阳性细胞、MVD、SOD活性、Nrf2蛋白表达量显著降低(P<0.05);与DFU组比较,Sal-L组、Sal-M组、Sal-H组、MET组大鼠体重、FBG水平、MDA含量、Keap1蛋白表达量均显著降低(P<0.05),创面愈合率、CD34阳性细胞、MVD、SOD活性、Nrf2蛋白表达量显著升高(P<0.05),其中Sal-L组与MET组差异无统计学意义(P>0.05)。结论Sal可能通过调节Nrf2/Keap1信号通路,增加DFU大鼠抗氧化能力,促进创面愈合。

Objective To explore the effects of salidroside(SAL)on nuclear transcription factor-E2 related factor 2/Kelch-like epichlorohydrin-related protein 1(Nrf2/Keap1)signaling pathway and wound healing in rats with diabetic foot ulcer(DFU).Methods Diabetes was induced in rats by feeding of a high-fat and high-glucose diet and intraperitoneal injecting of streptozotocin(STZ),and the back of the foot was shaved and cut to the fascia to create an ulcer wound with an area of approximately 3 mm×7 mm to establish DFU rat model.The rats were randomly allocated to a DFU model group;Sal-L(0.1 g(kg·d)),Sal-M(0.2 g/(kg·d)),Sal-H(0.3 g(kg·d))groups,metformin group(MET,0.65 g/(kg·d)),and set normal blood glucose wound rats as the control group(NC group),and all were gavaged daily for 2 weeks.The body mass and concentration of fasting-blood glucose(FBG)of all the rats were measured on the 7th and 14th days of treatment;the expression of CD34 was assessed by immunohistochemistry;the microvascular density(MVD)of the wounds was calculated;the levels of malondialdehyde(MDA)and superoxide dismutase(SOD)concentrations were measured biochemically,and the expression of Nrf2 and Keap1 proteins in the wound tissue was measured by Western blot.Results Prior to the start of treatment,there was no significant difference in the body masse between the groups,while the FBG of the DFU,Sal-L,Sal-M,Sal-H,and MET groups was higher than that of the NC group(P<0.05).On the 7th and 14th day of treatment,the body mass,FBG,MDA content,and Keap1 protein expression in the DFU,Sal-L,Sal-M,Sal-H,and MET groups were higher than those in the NC group(P<0.05);and the wound healing rate,CD34 positive cells,MVD,SOD activity,and Nrf2 protein expression were significantly lower(P<0.05).The body mass,FBG,MDA content,and Keap1 protein expression in the Sal-L,Sal-M,Sal-H,and MET groups were lower than those in the DFU group(P<0.05);and the wound healing rate,CD34 positive cells,MVD,SOD activity,and Nrf2 protein expression were significantly higher(P<0.05).However,there were no significant differences between the Sal-L and MET groups(P>0.05).Conclusions Sal may increase the antioxidant capacity and promote wound healing in rats with DFU via the Nrf2/Keap1 signaling pathway.