红花黄色素对糖尿病小鼠足溃疡创面愈合的影响及机制

Effect and mechanism of safflower yellow on wound healing of diabetic foot ulcers in mice

目的探讨红花黄色素(SY)对糖尿病小鼠足溃疡(DFU)创面愈合的影响及分子机制。方法取45只C57BL/6小鼠腹腔注射链脲佐菌素建立糖尿病模型。将糖尿病小鼠随机分为假手术组、模型组、低剂量SY干预组、高剂量SY干预组及高剂量SY联合胰岛素样生长因子-1(IGF-1)组,每组9只。DFU模型制备前,模型组小鼠不给予干预处理,低剂量SY干预组和高剂量SY干预组分别腹腔注射5、20 mg·kg^(-1)SY,高剂量SY联合IGF-1组腹腔注射20 mg·kg^(-1)SY和0.03 mg·kg^(-1)IGF-1。除假手术组外,其余4组小鼠通过切开足背部皮肤制备DFU模型;假手术组不制作足背部皮肤伤口,余手术步骤与模型组一致。于造模后第14天,用电子秤测量各组小鼠的体质量,采集尾静脉血测定空腹血糖,并使用小型游标卡尺测量创面宽度,然后处死小鼠收集创面组织,采用苏木精-伊红染色检测各组小鼠创面组织病理学变化,反转录-实时荧光定量聚合酶链反应检测各组小鼠创面组织中血小板衍生生长因子(PDGF)、血管内皮生长因子(VEGF)、α-平滑肌肌动蛋白(α-SMA)和I型胶原蛋白(collagen I)、蛋白酪氨酸磷酸酶1B(PTP1B)、晚期糖基化终产物(AGEs)mRNA的相对表达量,蛋白质印迹法检测各组小鼠创面组织中增殖标志物Ki-67、增殖细胞核抗原(PCNA)、凋亡相关蛋白(caspase-3、caspase-6、caspase-7)、p85磷脂酰肌醇-3-激酶(PI3K)和磷酸化蛋白激酶B(p-AKT)蛋白的相对表达量,酶联免疫吸附试验检测各组小鼠创面组织中肿瘤坏死因子-α(TNF-α)、白细胞介素(IL)-1β及IL-6水平。结果假手术组、模型组、低剂量SY干预组、高剂量SY干预组及高剂量SY联合IGF-1组小鼠血糖和体质量比较差异均无统计学意义(P>0.05)。高剂量SY干预组小鼠创面组织愈合率显著大于模型组、低剂量SY干预组及高剂量SY联合IGF-1组(P<0.01)。模型组、低剂量SY干预组及高剂量SY联合IGF-1组创面组织愈合率比较差异无统计学意义(P>0.05)。高剂量SY干预组小鼠创面组织中出现大量胶原纤维密集有序排列,并伴有大量新生血管;模型组、低剂量SY干预组及高剂量SY联合IGF-1组小鼠创面组织中胶原纤维稀疏,并伴有少量新生血管。高剂量SY干预组小鼠创面组织中PDGF、VEGF、α-SMA及collagen I mRNA相对表达量显著高于模型组、低剂量SY干预组、高剂量SY联合IGF-1组(P<0.01);高剂量SY干预组小鼠创面组织中PTP1B和AGEs mRNA相对表达量显著低于模型组、低剂量SY干预组、高剂量SY联合IGF-1组(P<0.01)。模型组、低剂量SY干预组、高剂量SY联合IGF-1组小鼠创面组织中PDGF、VEGF、α-SMA、collagen I、PTP1B及AGEs mRNA相对表达量比较差异无统计学意义(P>0.05)。高剂量SY干预组小鼠创面组织中Ki-67和PCNA蛋白相对表达量显著高于模型组、低剂量SY干预组、高剂量SY联合IGF-1组(P<0.01);caspase-3、caspase-6、caspase-7、p85 PI3K及p-AKT蛋白相对表达量显著低于模型组、低剂量SY干预组、高剂量SY联合IGF-1组(P<0.01)。模型组、低剂量SY干预组、高剂量SY联合IGF-1组中Ki-67、PCNA、caspase-3、caspase-6、caspase-7、p85 PI3K及p-AKT蛋白相对表达量比较差异无统计学意义(P>0.05)。高剂量SY干预组小鼠创面组织中TNF-α、IL-1β及IL-6水平显著低于模型组、低剂量SY干预组、高剂量SY联合IGF-1组(P<0.01)。模型组、低剂量SY干预组、高剂量SY联合IGF-1组小鼠创面组织中TNF-α、IL-1β及IL-6水平比较差异无统计学意义(P>0.05)。结论高剂量SY干预可通过提高血管生成、胶原形成及细胞增殖,降低胰岛素抵抗、炎症反应和细胞凋亡来促进小鼠DFU创面愈合,其机制可能与抑制PI3K/AKT通路有关。

Objective To investigate the effect and molecular mechanism of safflower yellow(SY)on wound healing of diabetic foot ulcer(DFU)in mice.Methods Forty-five C57BL/6 mice were injected intraperitoneally with streptozotocin to establish diabetic models.The diabetic mice were randomly divided into the sham operation group,model group,low-dose SY intervention group,high-dose SY intervention group,and high-dose SY combined with insulin-like growth factor-1(IGF-1)group,with 9 mice in each group.Before modelling,mice in the model group were not given any intervention,mice in the low-dose SY intervention group and high-dose SY intervention group were injected intraperitoneally with 5 and 20 mg·kg^(-1)SY,respectively,and mice in the high-dose SY combined with IGF-1 group were injected intraperitoneally with 20 mg·kg^(-1)SY and 0.03 mg·kg^(-1)IGF-1.Except for the sham operation group,the DFU model was established by incising the dorsal skin of the foot in the remaining four groups of mice.No wound on the dorsal skin of the foot was made in the sham operation group,and the remaining surgical steps were the same as those in the model group.The body mass of mice in each group was measured on day 14 after modelling using an electronic scale,tail vein blood was collected for fasting blood glucose measurement,and the wound width was measured using a small vernier caliper.Then,the mice were executed to collect the wound tissues.Hematoxylin-eosin staining was used to detect the histopathological changes in the wound tissues of mice in each group.Reverse transcription-quantitative real-time polymerase chain reaction was used to measure the relative expression levels of platelet-derived growth factor(PDGF),vascular endothelial growth factor(VEGF),alpha-smooth muscle actin(α-SMA),type I collagen(collagen I),protein tyrosine phosphatase 1B(PTP1B)and advanced glycation end products(AGEs)mRNA in the wound tissues of mice in each group.Western blot was used to detect the relative expression levels of proliferation marker Ki-67,proliferating cell nuclear antigen(PCNA),apoptosis-associated proteins(caspase-3,caspase-6,and caspase-7),p85 phosphatidylinositol-3-kinase(PI3K)and phosphorylated protein kinase B(p-AKT)protein in the wound tissues of mice in each group.Enzyme-linked immunosorbent assay(ELISA)was used to measure the levels of tumor necrosis factor-α(TNF-α),interleukin(IL)-1β,and IL-6 in the wound tissues of mice in each group.Results The differences in blood glucose and body mass of mice among the sham operation group,model group,low-dose SY intervention group,high-dose SY intervention group,and high-dose SY combined with IGF-1 group were not statistically significant(P>0.05).The healing rate of wound tissues in the high-dose SY intervention group was significantly greater than that in the model group,low-dose SY intervention group,and high-dose SY combined with IGF-1 group(P<0.01).There was no statistically significant difference in the healing rate of wound tissues among the model group,low-dose SY intervention group,and high-dose SY combined with IGF-1 group(P>0.05).In the high-dose SY intervention group,a large number of collagen fibers were densely and orderly arranged in the wound tissues,accompanied by a large number of neovessels;in the model group,low-dose SY intervention group,and high-dose SY combined with IGF-1 group,the wound tissues were sparsely populated with collagen fibers,accompanied by a small number of neovessels.The relative expression levels of PDGF,VEGF,α-SMA and collagen I mRNA in the wound tissues of mice in the high-dose SY intervention group were significantly higher than those in the model group,low-dose SY intervention group,and high-dose SY combined with IGF-1 group(P<0.01);the relative expression levels of PTP1B and AGEs mRNA in the wound tissues of mice in the high-dose SY intervention group were significantly lower than those in the model group,low-dose SY intervention group,and high-dose SY combined with IGF-1 group(P<0.01).The relative expression levels of PDGF,VEGF,α-SMA,collagen I,PTP1B and AGEs mRNA showed no statistically significant difference among the model,low-dose SY intervention,and high-dose SY combined with IGF-1 groups(P>0.05).The relative expression levels of Ki-67 and PCNA protein in the wound tissues of mice in the high-dose SY intervention group were significantly higher than those in the model group,low-dose SY intervention group,and high-dose SY combined with IGF-1 group(P<0.01);the relative expre-ssion levels of caspase-3,caspase-6,caspase-7,p85 PI3K,and p-AKT protein were significantly lower than those in the model group,low-dose SY intervention group,and high-dose SY combined with IGF-1 group(P<0.01).There was no statistically significant difference in the relative expression levels of Ki-67,PCNA,caspase-3,caspase-6,caspase-7,p85 PI3K and p-AKT protein among the model,low-dose SY intervention,and high-dose SY combined with IGF-1 groups(P>0.05).The levels of TNF-α,IL-1βand IL-6 in the wound tissues of mice in the high-dose SY intervention group were significantly lower than those in the model,low-dose SY intervention,and high-dose SY combined with IGF-1 groups(P<0.01).There was no statistically significant difference in the levels of TNF-α,IL-1βand IL-6 in the wound tissues of mice in the model,low-dose SY intervention and high-dose SY combined with IGF-1 groups(P>0.05).Conclusion High-dose SY intervention promotes DFU wound healing in mice by increasing angiogenesis,collagen formation and cell proliferation and reducing insulin resistance,inflammatory response and cell apoptosis,which may be related to the inhibition of the PI3K/AKT pathway.