HMGB1对心脏成纤维细胞MMP-9表达的影响及其机制研究

目的探讨高迁移率族蛋白1(HMGB1)对心脏成纤维细胞基质金属蛋白酶-9(MMP-9)表达的影响及其可能的机制。方法培养大鼠心脏成纤维细胞,予以100ng/ml浓度HMGB1干预,采用CCK-8检测细胞活力;Westernblot方法检测胞内及细胞上清中MMP-9水平,RAGE与TLR4表达水平及ERK1/2的磷酸化水平。结果 (1)HMGB1干预心脏成纤维细胞24小时,细胞活力与对照组相比无显著差异。(2)HMGB1干预心脏成纤维细胞24小时,胞内MMP-9蛋白水平显著降低(P<0.05),而细胞上清中MMP-9水平显著升高(P<0.05)。(3)HMGB1干预心脏成纤维细胞24小时,TLR4表达升高(P<0.05)而RAGE表达无显著差异。(4)HMGB1干预心脏成纤维细胞5分钟,ERK1/2显著活化(P<0.05)。(5)TLR4中和抗体(20ug/ml)阻断TLR4后,HMGB1+TLR4阻断组的p-ERK1/2表达较HMGB1干预组明显降低(P<0.05)。结论 HMGB1可能通过TLR4活化ERK1/2,促进心脏成纤维细胞分泌MMP-9,进而破坏心肌胶原结构,参与心肌重构。

Effects of HMGB1 on MMP-9 Expression in Rat Cardiac Fibroblasts

Objective To explore the effects of high mobility group box 1 （HMGB1） on matrix metalloproteinase-9 （MMP-9） expression in cardiac fibroblasts and its potential mechanism. Methods Rat cardiac fibroblasts were cultured and interfered with 100ng/ml recombinant HMGBl. Cell vitality was assessed by CCKS; intracellular and extracellular MMP-9, advanced glycation end products （RAGE） as well as toll-like receptor 4（TLR4） and extracellular regulated protein kinase （ERK1/2） phosphorylation levels were measured by Western blot. Results （1） Treated with HMGB 1 for 24 hours, HMGB1 did not cause any cytotoxic effects. （2） Treated with HMGBl for 24 hours, intracellular MMP-9 was significantly decreased （P 〈0.05）, but the level of MMP-9 in the supernatant in HMGBl-treated group was significantly increased （P 〈0.05）. （3） Treated with HMGBI for 24 hours, the expression of TLR4 in cardiac fibroblasts increased （P〈0.05）. （4） Stimulated with HMGBI for 5 minutes, the level of ERK1/2 phosphorylation in cardiac fibroblasts was significantly increased （P 〈0.05）. （5） Pre-treated with TLR4 neutral antibody （20ug/ml）, p-ERK1/2 expression of HMGB1＋anti-TLR4 group was significantly decreased as compared with HMGB 1-treated group （P 〈0.05）. Conclusion HMGBl may induce MMP- 9 secretion by activating TLR4-ERK1/2 signal pathway in cardiac fibroblasts, which was involved in myocardial remodeling.