IgA肾病肾组织AT1、AT2表达与肾小管上皮表型转化及肾间质血管病变发生学的关系

Study on the relationship of expression of AT1,AT2 in IgAN renal tissue with pathogenesis of proximal tubular cell transdifferentiation and renal interstitial vascular pathological changes

目的探讨肾内肾素-血管紧张素系统(RAS)与IgA肾病的肾小管上皮细胞表型转化及肾间质、肾血管病变的关系。方法应用免疫荧光、常规病理学、透射电镜等技术,观察15例Ⅱ级、15例Ⅲ级和20例Ⅳ-Ⅴ级共50例IgA肾病(IgA nephropathy,IgAN)肾活检组织的病理形态学特点,应用免疫组织化学Envision法检测肾组织内AT1、AT2、-αSMA和TGF-β的表达。结果50例IgAN中28例有肾小管-间质损害(占56%);肾小管上皮细胞、肾间质细胞和肾小球系膜细胞均有不同程度的AT1、AT2和TGF-β表达,-αSMA除在小球外细小动脉壁表达外,在肾小管上皮细胞、肾间质细胞和肾小球系膜细胞也都有表达。IgAN肾组织AT1(r=0.9977,P=0)、AT2(r=0.8367,P<0.05)和TGF-β(r=0.9901,P=0)的表达强度与肾间质血管病变程度呈正相关。结论肾小管上皮细胞AT 1及AT 2的表达与IgAN的肾小管和小球外小动脉病变程度有密切的相关性;AngⅡ参与了肾间质和球外血管病变的形成。

Objective To investigate the association of nephrogenous renin-angiotensin system （RAS） with pathogenesis of proximal tubular cell transdifferentiation and renal interstitial vascular pathological changes. Methods We observed the morphological changes of renal biopsy tissues by light microscopy and fluorescence microscopy. Expressions of AT1, AT2, TGF- β and α-SMA were detected by immunohistochemistry in 50 cases of IgAN. Results Among them, 28 cases （56%） showed renal interstitial fibrosis. Immunohistochemistry showed that AT1 and AT2 were expressed in the glomeruli, renal tubule, renal interstitium and vas. There were expressions of α-SMA in the thick wall of capillary, renal tubular cell, renal interstitium and mesangium. Conclusion The expession of AT1 and AT2 in renal tubular cells has close relationship with the pathological changes of renal tubule and vas outside glomeruli. AngII may have a positive correlation with the vascular and renal interstitial pathological changes outside glomeruli.