红芪多糖对糖尿病肾病db/db小鼠肾损伤的改善作用

Improving effects of Hedysarum polysaccharide on renal injury in db/db mice with diabetic nephropathy

目的研究红芪多糖(HPS)对糖尿病肾病(DN)db/db小鼠肾组织中转化生长因子-β_(1)(TGF-β_(1))、smad同源物3重组蛋白(smad3)、smad7在肾组织表达的影响。方法根据体质量将雄性db/db小鼠随机分为模型组(0.9%NaCl 0.2 mL·d^(-1))、阳性对照组(22.75 mg·kg^(-1)·d^(-1)厄贝沙坦)和高、中、低剂量实验组(200、100、50 mg·kg^(-1)·d^(-1)HPS),每组10只;另取10只同周龄SPF级雄性C57BL/6小鼠作为正常组(0.9%NaCl 0.2 mL·d^(-1))。6组小鼠每天灌胃1次,连续给药12周。于治疗前及治疗后第4、8、12周末检测小鼠血糖水平,用蛋白质印迹法检测TGF-β_(1)、smad3、smad7蛋白的表达水平。结果治疗后,模型组小鼠血糖水平均较正常组显著升高(均P<0.01);高、中剂量实验组小鼠的血糖水平均较模型组显著下降(P<0.05,P<0.01)。正常组、模型组、阳性对照组和高、中剂量实验组的TGF-β_(1)蛋白相对表达水平分别为0.71±0.16、1.66±0.18、1.00±0.17、0.88±0.15和1.23±0.15,smad3蛋白相对表达水平分别为0.89±0.32、2.26±0.35、1.24±0.31、1.05±0.30和1.67±0.35,smad7蛋白相对表达水平分别为1.66±0.03、0.60±0.03、1.10±0.07、1.48±0.08和0.97±0.09。高、中剂量实验组的上述指标与模型组相比,在统计学上差异均有统计学意义(P<0.05,P<0.01)。结论HPS可以通过调控血糖水平,抑制TGF-β_(1)、smad3及升高smad7的表达,改善肾纤维化,延缓DN发展进程。

Objective To study the effect of Hedysarum polysaccharides(HPS)on the expression of transforming growth factor-β_(1)(TGF-β_(1)),smad homologue 3 recombinant protein(smad3)and smad7 in renal tissue of db/db mice with diabetic nephropathy(DN).Methods According to their body weight,6-week-old male db/db mice were randomly divided into 5 groups:model group(0.9%NaCl 0.2 mL·d^(-1)),positive control group(22.75 mg·kg^(-1)·d^(-1)irbesartan)and experimental-H,-M,-L groups(200,100,50 mg kg^(-1)·d^(-1)HPS),with 10 mice in each group;another 10 SPF grade male C57BL/6 mice of the same week were selected as normal group(0.9%NaCl 0.2 mL·d^(-1)).The mice in the 6 groups were given intragastric administration once a day for 12 weeks.The blood glucose concentration of mice was measured before treatment and at the 4th,8th and 12th week after treatment.The expression levels of TGF-β_(1),smad3 and smad7 were detected by Western blotting.Results After treatment,the blood glucose levels of the model group was significantly higher than those of the normal group(all P<0.01);compared with the model group,the levels of blood glucose in the experimental-H,-M groups decreased significantly,and the differences were statistically significant(P<0.05,P<0.01).The relative expression levels of TGF-β_(1)protein in normal group,model group,positive control group and experimental-H,-M groups were 0.71±0.16,1.66±0.18,1.00±0.17,0.88±0.15 and 1.23±0.15;the relative expression levels of smad3 protein were 0.89±0.32,2.26±0.35,1.24±0.31,1.05±0.30 and 1.67±0.35;the relative expression levels of smad7 protein were 1.66±0.03,0.60±0.03,1.10±0.07,1.48±0.08 and 0.97±0.09;there were statistically significant differences between the experimental-H,-M groups and the model group(P<0.05,P<0.01).Conclusion Hedysarum polysaccharides can improve renal fibrosis and delay the development of diabetic nephropathy by regulating the level of blood glucose,inhibiting TGF-β_(1),smad3 and increasing the expression of smad7.