霉酚酸酯对阿霉素肾病大鼠的 保护作用及其机制研究

Protection and mechanism of mycophenolate mofetil on podocyte injury of adriamycin nephropathy rats

摘要:

目的 探讨霉酚酸酯（MMF）对阿霉素肾病（ADN）大鼠足细胞的保护作用，以及对肾组织 microRNAs（miRNAs）表达的影响。方法 将60 只SD 大鼠随机分为空白对照组（CTL 组）、ADN 模型组 （ADN 组）和MMF 干预组（MMF 组），ADN 组和MMF 组大鼠一次性尾静脉注射阿霉素6.5 mg/kg，7 d 后 开始灌胃给药。28 d 后处死所有受试大鼠，检测24 h 尿蛋白量、血尿素氮（BUN）、血清肌酐（Scr）水平， 以及肾组织病理学变化和足细胞凋亡情况；并借助基因芯片技术，分析肾组织miRNAs 表达的差异性；采用 实时荧光定量聚合酶链反应（qRT-PCR）检测肾组织miR-23a、miR-300-3p、miR-24 和miR-300-3c 的 表达。结果 3 组大鼠不同时间点体重、尿蛋白含量比较，差异有统计学意义（P <0.05）；与CTL 组大鼠比较， ADN 组大鼠体重减轻（P <0.05），肾组织损伤明显（P <0.05），尿蛋白、BUN、Scr 水平升高（P <0.05），足 细胞凋亡率较高（P <0.05）；而MMF 对ADN 组大鼠上述变化有改善作用，但是与CTL 组大鼠比较，差异有 统计学意义（P <0.05）。经基因芯片筛查和qRT-PCR 反应，ADN 组大鼠肾组织rno-miR-23a 和rno-miR- 300-3p 表达较CTL 组上调（P <0.05），rno-miR-24、rno-miR-300-3c 表达下调（P <0.05）；而MMF 组 大鼠肾组织中rno-miR-24、rno-miR-300-3c 表达较ADN 组上调（P <0.05），rno-miR-23a 和rno-miR- 300-3p 表达下调（P <0.05）。结论 MMF 具有抑制ADN 大鼠肾组织足细胞损伤和蛋白尿生成的作用，其机 制可能是对19 号和6 号染色体部分miRNAs 有干预作用。

Abstract:

Objective To discuss the protection role of mycophenolate mofetil (MMF) on podocyte injury of adriamycin nephropathy (ADN) rats and the effect on expression of miRNAs in renal tissue. Methods Totally 60 healthy male SD rats were randomly divided into CTL group, ADN group and MMF group. SD rats in ADN group and MMF group were injected adriamycin (6.5mg/kg) for building ADN models. After 7d, MMF was administrated orally once a day. The levels of 24-hour urinary protein quantity, blood urea nitrogen (BUN) and serum creatinine (Scr) were measured after 28d. Histopathological changes in renal tissue were graded through H&E, PAS and Masson staining. The differences and expression levels of miRNAs (including miRNAs-23a, miRNAs-300-3p, miRNAs-24 and miRNAs-300-3c) in kidney were measured by a biochip assay and qRT-PCR. Results The weight loss of animals (P < 0.05), the degree of kidney tissue injury (P < 0.05), the apoptosis rate of podocyte (P < 0.05) and the levels of BUN, Scr and urinary protein quantity (P < 0.05) in ADN group were higher than those in CTL group, which were attenuated with treatment of MMF (P < 0.05). The expression of rno-miR-23a and rno-miR-300-3p in ADN group was higher than those in CTL group, and the expression of rno-miR-24, rno-miR-300-3c was lower (P < 0.05). And the expression of rno-miR-24 and rno-miR-300-3c in MMF group was higher than those in ADN group, and the expression of rno-miR-23a, rno-miR-300-3p was lower (P < 0.05). Conclusions There are significant evidences that mycophenolate mofetil would attenuate podocyte damage in rats with adriamycin nephropathy by regulating miRNAs on chromosome 6 and 19.