艾塞那肽对胰岛素抵抗大鼠的肾损伤和核因子相关因子2/血红素加氧酶通路的影响

Effects of exenatide on renal injury and Nrf2/HO-1 pathway in insulin-resistant rats

目的探讨艾塞那肽对胰岛素抵抗(IR)大鼠肾损伤的影响,并分析其与核因子相关因子2(Nrf2)/血红素加氧酶(HO-1)信号通路的相关性。方法用高糖高脂饲料喂养建立IR大鼠模型;另选大鼠普通喂食作为正常组。按照体重将造模成功大鼠分为4组:模型组和低、中、高3个剂量实验组(1,2,4μg·kg^-1艾塞那肽),每组10只;均皮下注射,qd,正常组和模型组皮下注射等量0. 9%NaCl,连续给药6周。用酶联免疫吸附法检测8-羟基脱氧鸟苷(8-OHdG)水平,用羟胺法检测超氧化物歧化酶(SOD)活性,以硫代巴比妥酸法检测丙二醛(MDA)含量。用实时定量聚合酶链反应与免疫印迹法分别检测Nrf2、HO-1基因和蛋白的表达水平。结果给药后,正常组、模型组和高剂量实验组的8-OHdG水平分别为(13. 31±1. 73),(33. 58±2. 86)和(18. 67±1. 59) ng·L^-1;正常组、模型组和高剂量实验组的SOD水平分别为(238. 15±10. 21),(172. 11±6. 78)和(218. 37±10. 03) U·mg^-1;正常组、模型组和高剂量实验组的MDA水平分别为(3. 32±0. 58)(7. 87±1. 02)(4. 58±0. 42) nmol·g^-1;正常组、模型组、实验高剂量组的Nrf2蛋白相对表达量(OD值)为0. 85±0. 12,0. 18±0. 03和0. 68±0. 22;正常组、模型组、实验高剂量组HO-1蛋白相对表达量(OD值)为0. 89±0. 11,0. 12±0. 02和0. 65±0. 15,模型组与正常组比较或高剂量实验组与模型组比较,上述指标的差异均有统计学意义(均P <0. 05)。基因结果的趋势与蛋白一致。结论艾塞那肽可降低肾氧化应激水平进而改善胰岛素抵抗相关肾损伤,其可能通过激活Nrf2/HO-1信号通路发挥作用。

Objective To investigate the effect of exenatide on renal injury in rats with insulin resistance ( IR),and to analyze its relationship to nuclear factor - E2 - related factor 2 ( Nrf2 )/ heme oxygenase ( HO - 1) signaling pathway. Methods The SD rats were fed with high - sugar and high - fat diet to establish IR rat model. The other rats were fed with normal feeding as normal group. After making the model successfully,rats were randomly divided into 4 groups: model group, experimental low,middle,and high dose experimental groups ( 1,2,4 μg·kg^-1 exenatide),each group had 10 rats;subcutaneous injection was performed,qd;normal group and model group were given the same amount of saline subcutaneously for 6 weeks. The level of 8 -hydroxydeoxyguanosine ( 8 - OHdG) was detected by enzyme linked immunosorbent assay. The activity of superoxide dismutase ( SOD) was detected by hydroxylamine method,and the content of malondialdehyde ( MDA) was detected by thiobarbituric acid method. The expression of Nrf2 and HO - 1 mRNA and protein were detected by real - time quantitative polymerase chain reaction and Western blot,respectively. Results After administration,the levels of 8 - OHdG in normal group,model group and high dose experimental group were ( 13. 31 ± 1. 73 ),( 33. 58 ± 2. 86 ),( 18. 67 ± 1. 59) ng·L^-1;the level of the SOD in the above three groups were ( 238. 15 ± 10. 21),( 172. 11 ± 6. 78),( 218. 37 ± 10. 03) U·mg^-1;the level of the MDA in the above three groups were ( 3. 32 ± 0. 58)( 7. 87 ± 1. 02)( 4. 58 ± 0. 42) nmol·g^-1,respectively;the relative expression ( OD value) of Nrf2 protein in the above three groups were 0. 85 ± 0. 12,0. 18 ± 0. 03,0. 68 ± 0. 22;the relative expression( OD value) of HO - 1 protein in the above three groups were 0. 89 ± 0. 11,0. 12 ± 0. 02,0. 65 ± 0. 15. There were significant differences of the factors between model group and normal group or high dose experimental group and model group ( all P < 0. 05). The trend of gene results is consistent with that of protein. Conclusion Exenatide can reduce oxidative stress in kidney and further improve insulin resistance - related kidney injury,it may play a role by activating Nrf2 /HO - 1 signaling pathway.