血红素加氧酶1 对2 型糖尿病肾病 大鼠肾脏功能影响的研究

Effect of HO-1 on renal function of rats with type 2 diabetic nephropathy

摘要:

目的 通过复制糖尿病肾病大鼠模型，以药物干预改变糖尿病肾病大鼠肾脏中血红素加氧酶1 （HO-1）水平，从而探讨HO-1 对2 型糖尿病肾病大鼠肾脏功能的影响。方法 32 只SD 大鼠适应性喂养1 周后， 随机分成正常对照组、糖尿病肾病（DN）组、DN 氯化血红素组和DN 锌原卟啉组。除正常对照组外，其他 3 组复制糖尿病肾病模型，进行药物干预。各组大鼠用药4 周后进行取材，大鼠处死前禁食收集24 h 尿液，测 定大鼠24 h 尿量和尿肌酐（Ucr）。大鼠麻醉后心脏取血，分别检测血肌酐（Scr）和血胱抑素C（Cys-c）的 浓度，计算内生肌酐清除率（Ccr）。肾脏组织HE 染色观察大鼠肾脏组织结构是否异常，电镜下观察肾小球 和肾小管超微结构的改变，应用免疫组织化学和Western blot 技术对肾脏中HO-1 进行定位和定量分析。结 果 ① DN 组、DN 氯化血红素组和DN 锌原卟啉组Scr、Cys-c、Ucr、Ccr 与正常对照组比较，差异有统计 学意义（P <0.05），DN 组、DN 氯化血红素组和DN 锌原卟啉组Scr 和Cys-c 升高，Ucr、Ccr 降低，DN 锌原 卟啉组Scr 和Cys-c 增加幅度较DN 组和DN 氯化血红素组高。② HE 染色及电镜结果显示，正常对照组大鼠 肾脏组织结构无明显变化，其余3 组大鼠肾脏组织结构均有改变。肾脏组织结构破坏程度，DN 锌原卟啉组 >DN 组>DN 氯化血红素组。③ Western blot 结果显示，DN 氯化血红素组肾脏中HO-1 表达水平高于DN 组， DN 锌原卟啉组肾脏中HO-1 表达水平低于DN 组。结论 DN 氯化血红素组大鼠肾脏中HO-1 表达水平升高， 而DN 锌原卟啉组大鼠肾脏中HO-1 表达水平下降，DN 氯化血红素组大鼠肾脏的损伤指标以及肾脏组织形态 学的损伤程度轻于DN 锌原卟啉组，实验结果说明提高2 型糖尿病肾病大鼠肾脏中HO-1 表达水平可以减轻 肾脏损伤。

Abstract:

Objective To investigate the effect of heme oxygenase-1 (HO-1) on the renal function of rats with type 2 diabetic nephropathy by changing the expression of HO-1 in the kidneys of the rats through drug intervention. Methods After one week of adaptive feeding, 32 SD rats were randomly divided into normal control group, diabetic nephropathy (DN) group, DN hemin group and DN zinc protoporphyrin group with 8 in each group. The rats in each group were sacrificed 4 weeks later. The rats were fasted before sacrifice to collect 24-h urine. The volume of 24-h urine and urinary creatinine (Ucr) were measured. Blood samples were taken from the hearts of the rats after anesthesia. Serum creatinine (Scr) and blood cystatin C (Cys-C) concentrations were measured and the creatinine clearance rate (Ccr) was calculated. HE staining was used to observe the histological changes of renal tissues. The ultrastructural changes of glomeruli and renal tubules were observed by electron microscopy. Immunohistochemistry and Western blot were used for localization and quantitative analysis of HO-1 in the rat kidneys. Results Compared with the control group, the levels of Scr and Cys-C were increased (P < 0.05), Ucr and Ccr were decreased (P < 0.05) in the DN group, the DN hemin group and the DN zinc protoporphyrin group; Scr and Cys-C increased more in the DN zinc protoporphyrin group than in the DN and DN hemin groups. HE staining and electron microscopy showed that the renal tissue structures of the control group had no obvious change, but the structures of the kidney tissues changed in the other three groups. The degree of renal tissue structure damage was ranged as follows: DN zinc protoporphyrin group > DN group > DN hemin group. Western blot analysis showed that the expression of HO-1 in the kidneys of the DN hemin group was higher than that in the DN group, and the expression of HO-1 in the DN zinc protoporphyrin group was lower than that in the DN group. Conclusions The expression of HO-1 significantly increased in the rat kedneys of the DN hemin group, but decreased in the rat kedneys of the DN zinc protoporphyrin group. The indexes of renal injury and the degree of renal histomorphological injury in the DN hemin group were significantly lighter than those in the DN zinc protoporphyrin group. These experimental results showed that the expression of HO-1 in the kidneys of type 2 diabetic nephropathy rats could relieve kidney injury.