心房颤动患者心房组织中明胶酶的基因表达及活性变化

Changes in gelatinases expression and activity in human atria during atrial fibrillation

目的检测明胶酶及其内源性抑制剂金属蛋白酶组织抑制因子(TIMPs)和基质金属蛋白酶(MMPs)在心房颤动(房颤)患者心房组织中的表达和明胶酶活性的变化,探讨房颤患者心房结构重构的分子机制.方法 75例风湿性心脏瓣膜病(风心病)接受换瓣手术者分为三组,其中窦性心律组34例,阵发性房颤组11例,持续性房颤组30例;于术中获取右心耳组织,分别采用半定量逆转录-聚合酶链反应技术和免疫印迹法测定MMP-2、MMP-9、TIMP-1、TIMP-2的mRNA含量和蛋白含量,酶谱法测定MMP-2、MMP-9的活性.结果 (1) 与窦性心律组比较,MMP-2的mRNA 水平在阵发性房颤组、持续性房颤组心房组织中均明显增加(P<0.01,P<0.001);各组患者MMP-9的mRNA 水平相似.持续性房颤组MMP-2、MMP-9的蛋白表达水平较窦性心律组、阵发性房颤组均明显增加(P<0.01).阵发性房颤组MMP-2、MMP-9的蛋白表达水平较窦性心律组亦明显增加(均为P<0.05).(2) 与窦性心律组比较,持续性房颤组TIMP-1、TIMP-2的mRNA及蛋白表达水平均明显下调(P<0.05～0.01).(3) 与窦性心律组比较,持续性房颤组、阵发性房颤组MMP-2、MMP-9的活性均明显增加(P<0.05～0.01),持续性房颤组的MMP-9活性较阵发性房颤组亦明显增加(P<0.01). (4)MMP-2、MMP-9的mRNA及蛋白表达水平与左心房内径、房颤持续时间呈正相关(P<0.05～0.01),MMP-2、MMP-9的mRNA及蛋白表达水平分别与TIMP-2、 TIMP-1的mRNA及蛋白表达水平呈负相关 (均为P<0.01).结论房颤患者心房组织中MMP-2/TIMP-2、MMP-9/TIMP-1基因表达的调控失衡以及MMP-2、MMP-9活性的增高可能是影响胶原代谢、造成房颤时心房结构重构的分子机制之一,与房颤的发生和维持有关.

Objective To determine whether expression and activity of atrial gelatinases are altered in patients with atrial fibrillation (AF) Methods The right atrial tissue samples were taken from 75 patients with rheumatic heart disease who underwent heart valve replacement surgery 34 patients were in sinus rhythm, 11 patients had paroxysmal AF and 30 patients had persistent AF The mRNA and protein level of MMP 2,MMP 9,TIMP 1,TIMP 2 were measured by semi quantitative reverse transcription polymerase chain reaction (RT PCR) and Western blotting analysis respectively The activity of MMP 2 and MMP 9 was measured by zymographic analysis Results (1)The mRNA level of MMP 2 increased significantly in the persistent AF group followed by the paroxysmal AF group compared with the sinus rhythm group( P <0 01, respectively) MMP 9 mRNA expression remained compatible within groups ( P >0 05) MMP 2 and MMP 9 protein expression was prominent in the persistent AF group compared with the sinus rhythm and paroxysmal AF groups ( P <0 01),the significant difference was also observed between the paroxysmal AF and sinus groups ( P <0 05) (2) TIMP 1 and TIMP 2 expression at mRNA and protein level were all down regulated in the persistent AF group compared with the sinus rhythm group ( P <0 05), however, the trends of reduction did not reach statistical significance in the paroxysmal AF group ( P >0 05) except that of the mRNA level of TIMP 2 ( P <0 05) (3) The activity of MMP 2 and MMP 9 significantly increased in both paroxysmal AF and persistent AF groups compared with the sinus rhythm group ( P <0 05) The significant difference in MMP 9 was also observed between the persistent AF and paroxysmal AF groups ( P <0 01) (4) MMP 2 and MMP 9 expression at mRNA and protein level were positively correlated with left atrial dimension and AF duration ( P <0 05) and were negatively correlated with the mRNA and protein level of TIMP 2 and TIMP 1 respectively ( P <0 01) Conclusions The upregulation of MMP 2,9 gene expression and activity , along with the selective downregulation of TIMP 1,2 may have contributed to the atrial structural remodeling during AF through influencing collagen metabolism