百令胶囊对肾小管间质纤维化大鼠肾小管上皮-间质转分化的干预作用

目的探讨百令胶囊对小管间质纤维化大鼠小管上皮-间质转分化的干预作用。方法利用腺嘌呤诱导建立肾小管间质纤维化大鼠模型,实验SD大鼠随机分为模型组、干预组、对照组各30只,分别于实验第7周、12周、17周收获动物各10只,进行功能学和肾脏组织病理学检测和观察。利用免疫组织化学对骨形态发生蛋白-7(BMP-7)、转化生长因子-β1(TGF-β1)和α-平滑肌肌动蛋白(-αSMA)在肾小管间质纤维化大鼠中的表达变化进行动态观察及百令胶囊的干预影响。结果实验第7周模型组大鼠即表现出大量蛋白尿、小管损伤、间质的轻度纤维化和炎症细胞浸润(P<0.01);随病程进展,上述病变呈进行性加重(P<0.01)。百令胶囊干预组动物在实验第7周、12周功能学组织学的改善同实验组相比有明显差异(P<0.01),17周后二者无显著差异。免疫组织化学显示百令胶囊12周前能显著上调BMP-7的表达和降低-αSMA和TGF-β1在肾脏小管间质中的表达(P<0.01),12周后这种变化无差异。结论百令胶囊在发病早期通过有效干预上皮-间质转分化达到改善肾脏纤维化的作用,随着肾小管间质纤维化程度的加重,百令胶囊逐渐失去其阻断作用。

Bailing Capsule in Preventing Epithelial- Mesenchymal Transition in Rats with Tubulointerstitial Fibrosis

Objective To explore the effect of Bailing capsule on epithelial-mesenchymal transition( EMT) in rats with adenine-in-duced tubulointerstitial fibrosis. Methods Tubulointerstitial fibrosis animal models were established and SD rats were divided into mo-del group ( n = 30), treatment group ( n = 30) and control group( n = 30), randomly. Experimental rats were harvested at 7 w, 12 w,17 w after onset of experiment and functional evaluations were performed. Histology, immunohistology were examined to investigateboth histolopathology changes and the expression of bone morphogenic protein-7 (BMP-7), transforming growth factor-β1 (TGF-β1 )and a-smooth muscle actin (α-SMA) in kidneys at three time points mentioned above, respectively. Results Compared with controlgroup, 24 h urinary protein in model group lost increasingly and significantly difference appeared at three time points relative to controlgroup ( P ＜ 0.01 ). Urinary NAG in model group was markedly higher than that in control group from 7 w after onset (P ＜ 0.01 ) andwas increasingly raised at 12 w and 17 w (P＜0.01). The value of blood BUN and Cr in model group increased at 7 w (P＞0.05) rel-ative to control group. There was significant difference at 12 w and 17.w (P ＜ 0.01 ). Histologically, kidneys in model group, at 7 w,exhibited tubular casts and gently tubular dilation, granuloma in cortex, mononuclear cells infiltration in tubulointerstitial areas, andmild interstitial fibrosis. At 12 w, the degree of tubular injury and tubulointerstitial fibrosis gradually aggravated. Up to 17 w, diffusetubular dilation or atrophy was observed and focal tubules disappear. Diffuse interstitial fibrosis was exhibited. In normal kidneys, im-munohistochemistry suggested that the light expression of BMP-7 was detected in proximal renal tubular epithelial cells and marked ex-pression was identified in distal tubule, collecting duct, and renal tubular epithelial in junction area between cortex and medulla. How-ever, the expression of BMP-7 in kidneys of model group significantly decreased with increasing tubulointerstitial fibrosis and was nega-tive correlation with the expression of TGF-β1(r = -0. 981 P＜0.01) and α-SMA (r= -0.975 P＜0.01). Bailing capsule ad-ministration protected the expression of BMP-7 and reduced TGF-β1 and α-SMA expression before 12 w(P＜ 0.01 ). Conclusions Ourstudy shows an anti-fibrotic reno-protective function of Bailing capsule in rats with tubulointerstitial fibrosis via prevention of epithelial-mesenchymal transition at early stage. However, the beneficial effect lost with increasing tubulointerstitial fibrosis.