Relationship Between C-1562T Polymorphism Of Matrix Metalloproteinase-9(MMP-9) Functional Promoter And Acute Coronary Syndrome

BackgroundAcute coronary syndrome is the result of plaque disruption superimposedthrombosis formation. Atherosclerosis is the name of the process inwhich deposits of fatty substances, cholesterol, cellular waste products,calcium and other substances build up in the inner lining of an artery.This buildup is called plaque. It usually affects large and medium-sizedarteries. Plaques can grow large enough to significantly reduce theblood's flow through an artery. But most of the damage occurs whenthey become fragile and rupture. Plaques that rupture cause blood clots toform that can block blood flow or break off and travel to another part ofthe body. If either happens and blocks a blood vessel that feeds the heart,it causes ACS. The damage to the endothelium may stimulate artery wallcells to produce other substances that result in further buildup of cells.Research suggests that inflammation in the circulating blood may play animportant role in triggering heart attacks. When inflammatory reactionhappens, inflammatory cells release substance which can degradationextracellular matrix(such as mmp-9). The degradation of ECM was aprerequisite for histoleucocyte and VSCMs to migrate through coronary atherosclerosis. Plaques become fragile when fabrics cap thinningz.When plaque tended to rupture, acute coronary syndrome happened. Asthe main protease to degradate ECM, MMPs had been a hot spot in recentyears. MMP-9 belonged to Gelatinases B, and it was famous for theability of degrading collagenase and interstitial collagen. It coulddegraded denatured collagens, typeⅣ,Ⅴ,Ⅶ,Ⅹ, andⅫcollagens,which was concerned with the degradation of ECM of atheroscleroticplaque. It was showed that MMP-9 level was significantly high in AMIand UAP patients. The activity of romp-9 was tightly controlled at severaldifferent cellular levels. In recent years, some researches have presumedsome genovariation to predict coronary artery disease and acute coronarysyndrome. The polymorphism of MMP-9 may be one of these regulators.ObjectivePolymerase chain reaction (PCR) and restriction fragment lengthpolymorphism were used to investigate the relation of Matrixmetalloproteinase-9 polymorphism to acute coronary syndrome. Severityof coronary artery diseased was also analyzed.Method1,Venous blood (7ml) was collected from each subject into tubescontaining 50 mmol of EDTA per liter, and genomic DNA wasisolated by the phenol-chloroform method.2,Polymorphic regions of each mmp-9 were amplified by the polymerase chain reaction (PCR).3,The PCR products were digested by restriction enzyme NspI at37°for 5 hours. The extreme products were denatured and separatedby agarose-gel electrophoresis.4,All calculations were performed with SPSS statistical software.Measured variables were compared between patients with acutecoronary syndrome and controls with use of the unpaired Student'st-test. Categorical variables were compared with use of thechi-square test. Allele frequencies were estimated by thegene-counting method.Results1,The MMP-9 polymorphism may be susceptible to ACS.2,No significant difference was found between the AMI and UAPsubgroups.3,The polymorphism of MMP-9 had no significant effect on theseverity of coronary stenosis.