Bailing Capsule in Preventing Epithelial- Mesenchymal Transition in Rats with Tubulointerstitial Fibrosis / 实用儿科临床杂志

ABSTRACT

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.