黄芪当归合剂对间质纤维化肾脏中细胞外基质降解系统的调控作用

目的:深入研究黄芪当归合剂抑制肾脏纤维化的作用机制。方法:Wistar雄性大鼠随机分为假手术组、单侧输尿管梗阻模型组和黄芪当归合剂治疗组(14 g.kg-1.d-1)。在治疗后的第3,7,10天观察各组纤维化程度,测定纤溶酶原激活物抑制物-1(PAI-1)、组织型纤溶酶原激活物(t-PA)及活性PAI-1,t-PA的表达,检测基质金属蛋白酶(MMP-9,MMP-2)及组织型基质金属蛋白酶抑制剂-1(TIMP-1)活性。结果:黄芪当归合剂明显减轻输尿管梗阻导致的肾间质纤维化。在各时间点,模型组总PAI-1及活性PAI-1的表达较假手术组明显增高,而经黄芪当归合剂治疗后PAI-1表达及活性较模型组显著降低;模型组中t-PA仅在第3天时增高,同时黄芪当归合剂治疗组较模型组明显降低。整个观察期中模型组和黄芪当归合剂治疗组的MMP-2,9活性均较假手术组明显增高,但2组间无统计学差异;模型组的TIMP-1活性在第7天和第10天时显著增高,而黄芪当归合剂治疗组较模型组显著降低。结论:黄芪当归合剂可以改善肾组织PAs/PAIs及MMPs/TIMPs系统的失衡而减少细胞外基质的积聚,可能是其抑制肾间质纤维化的机制之一。

Modulation of aberrant extracellular matrix degradation systems by Astragali Radix and Angelicae Sinensis Radix decoction (A&A) in interstitial fibrotic kidney

Objective: The imbalance between extracellular matrix (ECM) synthesis and degradation induces the excessive ECM deposition and thus renal fibrosis. The decoction (A&A) which is a combination of two Chinese herbs, Astragalus membranaceus var. mongholicus and Angelica sinensis, has been shown to alleviate ECM production in animal models of chronic kidney diseases. In this paper, the effect of A&A on ECM degradation was investigated with interstitial fibrosis in rats. Method: Male Wistar rats were randomly divided into sham, unilateral ureteral obstruction (UUO) and UAA (UUO plus A&A administration) groups. After administration of A&A (14 g·kg^-1·d^-1) by gavage for 3, 7 and 10 days, morphological changes were evaluated by HE, PAS and Sirius red staining technique. The expression of plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (t-PA), the activity of PAI-1 and t-PA were determined by ELISA. The activity of matrix metalloproteinases (MMP-9, MMP-2), tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) were evaluated by gelatin zymography or reverse gelatin zymography, respectively. Result: Morphological analysis showed severe interstitial mononuclear cells infiltration, tubular atrophy, renal fibrosis and collagen expression in kidneys of UUO group, which was reduced by A&A administration (P<0.05, UAA vs UUO group). Compared with the sham group, the expression of PAI-1 was significantly increased in UUO group by 63%, 91% and 112% at day 3, 7 and 10 respectively; and there were a remarkable decrease in UAA group by 44%, 43% and 52% at day 3, 7 and 10. The expression of active PAI-1 was strikingly increased in UUO group at day 3, day 7, and day 10. The active PAI-1 was decreased in UAA group at day 7 and day 10. The expression of t-PA was increased in UUO group only at day 3, P<0.05), meanwhile decreased in UAA group. But the expression of active t-PA was shown no significantly difference among the three groups. For MMP-2 and MMP-9 activity, they were significantly higher compared with the sham group in UUO group, but no significantly change after A&A treatment. The TIMP-1 activity was significantly increased in UUO group by 28% and 63% at day 7 and 10 respectively, significantly decreased in UAA group by 40% and 39% at the same time point. Conclusion: The anti-fibrosis effects of A&A might be associated with modulating the imbalance of PAs/PAIs system as well as MMPs/TIMPs system, thereby alleviate ECM accumulation and interstitial fibrosis.