肾上腺髓质素对大鼠Thy-1肾炎肾小球系膜细胞增生和Ⅳ型胶原、纤连蛋白沉积的影响

Effect of Adrenomedullin on the Proliferation of Mesangial Cells and Accumulation of Type Ⅳ Collagen and Fibronectin in the Glomeruli of Rats with Anti-thy1 Glomerulonephritis

目的研究肾上腺髓质素(adreomedullin,AM)对大鼠Thy-1系膜增生性肾炎肾小球系膜细胞增生和细胞外基质合成的影响,为其用于防治肾小球疾病提供实验依据。方法自制兔抗大鼠Thy-1多克隆抗体,建立大鼠Thy-1系膜增生性肾炎模型,随机分为对照组、模型组和AM治疗组。分别于3、5、7d处死大鼠,每组至少处死6只,取其肾脏,分别作组织切片细胞核苏木精染色以及增殖细胞核抗原(PCNA)、α-平滑肌肌动蛋白(α-SMA)免疫组化染色,应用图像分析技术行肾小球细胞数、PCNA阳性细胞数和α-SMA表达强度检测。经抽提肾组织蛋白,用Western Blot法检测肾组织Ⅳ型胶原(ColⅣ)和纤连蛋白(FN)的表达。结果与对照组相比,模型组和治疗组3、5、7d时,肾小球细胞数、PCNA阳性细胞数及α-SMA表达强度均明显增高(P<0.05或P<0.01);于3d时,治疗组的上述各指标均较模型组显著降低(P<0.01),而5、7d时则差异不显著。与对照组相比,模型组和治疗组3、5、7d时,肾组织ColⅣ、FN表达明显增强(P<0.01);于3d时,治疗组肾组织ColⅣ、FN表达均显著降低(P<0.01),而5、7d时则差异不明显。结论AM对大鼠Thy-1肾炎早期肾小球细胞增生及基质合成有一定抑制作用。

Purpose To study the effect of adrenomedullin（AM） on the proliferation of mesangial cells and accumulation of extracellular matrix（ECM） in the glomeruli of rats with anti-thy1 glomerulonephritis to provide experimental basis for treating human glomerulopathy. Methods Anti-thy1 glomerulonephritic rats were produced by injecting rabbit polyclonal antibody against thyrnic Thy-1 antigen of rat. Experimental rats were randomly divided into control group, model group and AM treatment group. Renal samples were taken from more than 6 sacrificed rats for each group at 3, 5, 7 day. Renal tissue sections were stained by hematoxylin staining to detect cell nuclei, and by immunohistochemistry to detect the expressions of proliferating cell nucleus antigen（PCNA） and s-smooth muscle actin（α-SMA）. Protein was extracted from renal tissue to detect the expressions of type IV collagen （Col Ⅳ） and fibronectin（FN）. Results Compared with control group, the total cell number, PCNA positive cell number and the α-SMA staining intensity in model group and AM treatment group increased significantly （P〈0.05 or P〈0.01） from day 3 to day 7.They all decreased significantly in AM treatment group at 3 d, but were not changed statistically at 5 d and 7 d. Compared to model group （P〈0.01）. Compared with control group, the expressions of Col Ⅳ and FN in model group and AM treatment group increased significantly （P〈0.01） from day 3 to day 7. Both of them decreased significantly in treatment group, but not changed statistically at 5 d and 7 d, compared to model group（P〈0.01） at day 3. Conclusions Adrenomedullin could partly inhibit mesangial cells proliferation and glomenalar ECM accumulation in early phase of rat anti-thy1 glomenalonephritis in vivo.