嘌呤霉素肾病模型肾组织微小RNA的差异性表达及雷至胶囊的干预作用

目的:观察嘌呤霉素氨基核苷(puromycin aminonucleoside,PAN)肾病模型鼠肾组织微小RNA(microRNAs,miR-NAs)差异性表达的特征及其与足细胞裂隙膜(slid diaphragm,SD)关键结构分子nephrin,podocin和骨架蛋白synaptopodin表达的关系；阐明雷至胶囊(Leizhi capsule,LZC)在体内通过调控模型鼠肾组织miRNAs差异性表达而改善足细胞nephrin,podocin,synaptopodin表达,减少蛋白尿的机制.方法:将50只雄性Wistar大鼠随机分为空白组(A)、模型组(B)、雷至胶囊组(C,5 mL·kg-1·d-1)、雷公藤多苷组(D,10mL·kg-1 ·d-1)和缬沙坦(E,7.5 mL· kg-1·d-1)组.除A组外,其余各组大鼠一次性经颈静脉注射PAN(100 mg·kg-1)而建立PAN肾病模型.造模后第2天灌胃给药,A,B组大鼠用生理盐水干预,共10 d.造模前及造模后第3,9天称量各组大鼠体重,并检测24h尿蛋白排泄量(urinary protein ration,Upro).造模后第11天,处死全部大鼠,采集血液和肾组织,观察血清生化指标血清白蛋白(albumin,Alb),血清肌酐(serum creatinine,Scr),血清尿素氮(blood urea nitrogen,BUN),肾小球超微结构(足细胞足突形态)以及肾组织dicer酶,nephrin,podocin,synaptopodin表达；同时,借助生物芯片(biochip)技术,分析肾皮质miRNAs差异性表达的特征,并且,借助荧光实时定量聚合酶链反应(Real-time PCR)验证mo-miR-23a,rno-miR-300-3p,rno-miR-24,rno-miR-30c等的差异性表达量.结果:在PAN诱导下,模型鼠出现蛋白尿、肾功能减退、低白蛋白血症、足细胞足突融合；在模型鼠肾组织中,dicer酶影响足细胞nephrin,podocin,synaptopodin表达；上调rno-miR-23a,mo-miR-300-3p表达,下调mo-miR-24,rno-miR-30c表达；差异性表达的miRNAs包括rno-miR-24,rno-miR-30c,rno-miR-23a,rno-miR-300-3p等.雷至胶囊能改善PAN肾病模型鼠的一般情况、蛋白尿、血清BUN、足细胞足突融合；还能减少模型鼠肾组织dicer酶表达,增加足细胞nephrin,podocin和synaptopodin表达；减弱在模型鼠肾组织中上调的rno-miR-23a,rno-miR-300-3p,增强在模型鼠肾组织中下调的rno-miR-24,rno-miR-30c等.结论:PAN在体内通过dicer酶/miRNAs差异性表达途径而影响模型鼠肾组织miRNAs表达,干预足细胞nephrin,podocin,synaptopodin表达,破坏足细胞结构和功能,产生蛋白尿；雷至胶囊可以减少PAN肾病模型鼠蛋白尿,其机制可能是干预dicer酶/miRNAs差异性表达途径,调控足细胞nephrin,podocin,synaptopodin表达,改善足细胞的结构与功能.

Differential expressions of miRNAs in kidney in puromycin aminonucleoside nephropathy model and intervened effects of Leizhi capsule

Objective: To observe the differential expression characteristics of microRNAs (miRNAs) in renal tissues in puromycin aminonucleoside(PAN) nephritic model, and its relationship with key structural molecules of slid diaphragm(SD) nephrin and podocin and expression of skeleton protein synaptopodin; and to explore the in vivo mechanisms of Leizhi capsule (LZC) for ameliorating the expressions of nephrin, podocin and synaptopodin and reducing proteins by regulating the modal rat renal tissues miRNAs. Method: Fifty male Wistar rats were randomly divided into five groups: the control group(A), the model group(B), the LZC-treated group(C), the multi-glycoside of Tripterygium wilfordii(GTW)-treated group(D) and the valsartan-treated group(E). Apart from group A, all of rats in the remaining groups are injected with PAN (100 mg·kg^-1) through jugular veins to establish the PAN nephropathy model. On the 2nd day after PAN nephropathy model was established, group C was orally administered with LZC (5 mL·kg^-1·d^-1) in group C, group D GTW(10 mL·kg^-1·d^-1), and E group valsartan(7.5 mL·kg^-1·d^-1), while groups A and B were intervened with physiological saline, for 10 days. Body weight and 24 h urinary protein ration (Upro) in all rats were measured at day 0, 3, and 9. All rats were sacrificed at day 11 after the establishment of the model, and their blood and renal tissues were collected to observe such blood biochemical indicators including albumin (Alb), serum creatinine (Scr),blood urea nitrogen (BUN) and glomerular ultrastructure (podocyte foot process form) and expressions of dicer enzyme, nephrin, podocin and synaptopodin in renal tissues. Meanwhile, the differential expressional characteristics of miRNAs in renal cortex were analyzed by biochip assay. Additionally,the differential expressional volumes of rno-miR-23a, rno-miR-300-3p, rno-miR-24 and rno-miR-30c were measured by real-time PCR. Result: Proteinuria, renal dysfunction, hypoproteinemia and podocyte foot process fusion were investigated in model rats induced by PAN. In renal tissues of PAN nephropathy model rats, dicer enzyme affected the expressions of nephrin, podocin and synaptopodin in podocytes, up-regulated the expressions of rno-miR-23a and rno-miR-300-3p, and down-regulated the expressions of rno-miR-24 and rno-miR-30c. The miRNAs with differential expressions included rno-miR-24, rno-miR-30c, rno-miR-23a and rno-miR-300-3p. LZC could improve the general state, proteinuria, serum BUN and podocyte foot process fusion of PAN nephropathy model rats, reduced the expressions of dicer enzyme, increased the expressions of nephrin, podocin and synaptopodin in podocytes, weakened the up-regulated rno-miR-23a and rno-miR-300-3p, and strengthened the down-regulated rno-miR-24 and rno-miR-30c in renal tissues. Conclusion: PAN in vivo impacts the expressions of miRNAs in renal tissues, intervenes the expressions of nephrin, podocin and synaptopodin in podocytes, damages podocyte structures and functions and generates proteinuria by means of differential expression of dicer enayme/miRNAs. LZC can reduce proteinuria in PAN nephropathy model rats. Its mechanism may intervene dicer enayme/miRNAs differential expression, regulate nephrin, podocin and synaptopodin in podocytes and improve podocyte structures and functions.