替普瑞酮对大鼠梗阻性肾病间质纤维化的影响

Effect of geranylgeranylacetone on inhibiting tubulointerstitial fibrosis in unilateral ureteral obstruction rats

目的探讨替普瑞酮（GGA）对大鼠梗阻性肾病模型（UUO）肾间质纤维化的影响和可能机制。方法15只SD大鼠随机分成3组：假手术组、UUO模型组和GGA治疗组，每组5只。从建立UUO模型前1d开始，GGA治疗组和模型组分别给予400mg／kgGGA和溶媒（0．05％阿拉伯树胶＋0．008％维生素E）灌胃，每天1次，术后第7天处死大鼠。常规染色观察肾脏组织病理改变。间接免疫荧光和Western印迹检测肾脏E-钙黏蛋白（E—cadherin）和α-平滑肌肌动蛋白（α-SMA）的水平。TUNEL染色和PCNA免疫组织化学染色分别观察肾小管上皮细胞的凋亡和增生情况。结果GGA能诱导肾脏特异性高表达热休克蛋白72（HSP72）。与UUO模型组相比，GGA治疗组肾小管损伤和肾问质纤维化的程度明显减轻『肾小管损害百分比（48．7％±1．3％比65．8％±7．3％）；肾间质损害分值（0．40±0．08比1．36±0．50），P均〈0．05】；E—cadherin蛋白水平增加，α-SMA蛋白水平降低（P均〈0．05）；每高倍视野中TUNEL阳性和PCNA染色阳性的细胞数显著减少（分别为6．78±1．25比2．81±0．63，57．61±5．42比17．66±1．38，P均〈0．05）。结论GGA可能通过抑制肾小管上皮细胞的凋亡，延缓大鼠梗阻性肾病肾间质纤维化的进程。

Objective To investigate the effects of geranylgeranylacetone （GGA） on tubulointerstitiai fibrosis in unilateral ureteral obstruction （UUO） rats. Methods Fifteen male Sprague-Dawley rats weighing 200-250 g were randomly divided into three groups： sham group, model group and GGA group. Rats subjected to UUO operation were treated with daily oral dose of vehicle（5% gum Arabic and 0.008% tocopherol） or 400 mg/kg GGA one day before UUO operation until being sacrificed. Five rats were sacrificed at day 7 in each group. Routine kidney pathology was examined. Expression of E-cadherin and α-SMA protein was assessed by indirect immunofluorescence and Westeru-blot. Tubular apoptosis was detected by determinal deoxynucleotidyl transferase （TdT）-mediated deoxyurideine triphosphated （dUTP） nick-end labeling （TUNEL） assay. Proliferating cell nuclear antigen （PCNA） was examined by immunohistochemistry. Results As compared to model group, treatment with GGA markedly elevated HSP72 level in kidneys, significantly reduced tubular lesions and attenuated interstitial fibrosis （48.7%±1.3% vs. 65.8%±7.3%, score 0.40±0.08 vs. 1.36±0.50, P〈0.05）; EMT was reduced by up-regulation of E-cadherin, down-regulation of α-SMA （P〈O.05）, and apoptotic tubular cells as well as proliferative tubular cells were decreased（6.78± 1.25 vs. 2.81±0.63,57.61±5.42 vs. 17.66±1.38, respectively, all P〈0.05） in GGA group. Conclusion GGA can attenuate tubulointerstitial fibrosis in rat UUO model, at least in part, by inhibiting tubular apoptosis.