自发性狼疮小鼠明胶酶A、B的表达变化及肾乐的影响

EFFECTS OF " SHENLE" ON THE EXPRESSIONS AND ACTIVITIES OF GELATINASE A AND B IN AUTOIMMUNE MRL/lpr MICE

为探讨MRL/lpr自发性狼疮小鼠肾脏明胶酶A(MMP 2 )与明胶酶B(MMP 9)的表达变化 ,明确中药复方肾乐的调节作用及机制 ,将 90只 8周龄狼疮小鼠随机分为肾乐治疗组、甲基强的松龙 (MPS)治疗组与对照组 ,肾乐治疗组经饲料服用肾乐 ( 4g·kg-1·d-1) ,MPS治疗组腹腔注射甲基强的松龙 2 5mg·kg-1·d-1,共 2 0周。观察 3组小鼠的存活率、蛋白尿、肾功能与肾脏病理改变。并利用免疫组化检测明胶酶A、B的表达变化 ,明胶酶谱法检测肾脏与尿液明胶酶A、B的活性变化。结果发现 ,肾乐、MPS与对照组相比均能够延长狼疮小鼠的存活率 ( 70 %∶80 %∶5 0 % )、减少蛋白尿的出现比率 ( 4 0 %∶33.3%∶80 % )并减轻肾脏病理改变 ;与 8周龄狼疮小鼠比较 ,2 8周龄狼疮小鼠肾小球内明胶酶A、B的表达明显增加 ,肾脏与尿液中明胶酶A、B的活性均明显增加 ,与狼疮性肾炎的病理损害密切相关。提示肾乐与MPS能够明显抑制肾小球明胶酶A、B的表达及活性变化 ,这可能是肾乐减轻MRL/lpr自发性狼疮小鼠肾脏病理损害的主要机制之一。

To determine whether increased expressions of gelatinase A(MMP-2) and gelatinase B(MMP-9) occur in vivo in autoimmune MRL/lpr mice model and to investigate the modulation effects of 'shenle.' Shenle (4g·kg -1 ·d -1 ,orally) or methylprednisolone(MPS,25mg·kg -1 ·d -1 ,ip)was administered daily to MRL/lpr mice at the age of 8 weeks. The activities of MMP-2/9 by gelatin zymography were compared in kidney protein extracts and urine. After treatment for 20 weeks, a progressive reduction in positive proteinuria number/total mice (40% vs.33 3% vs.80%, proteinuria over 300 mg/dl as positive) and an elevated survival rate (70% vs.80% vs. 50%) were found in 'shenle' and MPS groups compared with the control group. Histological analysis of kidney tissues indicated that both 'shenle' and MPS could inhibit the mesangial proliferation and renal sclerosis. Using SDS-PAGE gelatin zymography, we have identified increased expressions of both latent and activated form enzymes of MMP-2/9 in urine and kidney extraction. Immunohistochemical staining showed both MMP-2 and MMP-9 were obviously up-regulated within glomerulus in control group. 'Shenle' as well as MPS suppressed the expression of both latent and activated form of MMP-2/9. These in vivo results suggested that MMP-2/9 expressions might play an important role in murine lupus nephritis. 'Shenle' delayed the development of glomerulonephritis and improved survival in MRL/lpr mice probably by suppressing the expressions and activities of MMP-2/9.