Study On The Relation Between Matrix Metalloproteinase-9 Polymorphism(C-1562T) And Acute Cerebral Infarction In Han Population Of China

Cerebral infarction (CI) refers to a disease of ischemia that causes necrosis and softening of the brain tissue and the patients often have corresponding nervous system symptoms such as hemiplegia and aphasia. The persons who suffer from the disease are usually more than 50 years old with cerebral arteriosclerosis. It has become a great danger to human health with it's high morbidity and mortality as a kind of multifactor disease that includes environmental and genetic factors .In recent years, researches have been made in the new field on the potential influence of gene polymorphism and gene mutation on cerebral infarction. It is believd that gene structure and expression abnormality, including mutation, shifting, inserting and lacking of the gene may be the basic reasons for cerebral infarction. This papermakes a research on the relationship between MMP-9 ( Matnix metalloproteinase-9 ) and cerebral infarction, especially on genetic polymorphism in MMP-9 promoter( C-1562T ) to make clear whether it is a dangerous genetic factor of cerebral infarction. Objective: To investigate the relationship between MMP-9 serum level and polymorphism( C-1562T) in patiens and acute cerebral infarction in Han population.Methods: sixty-five patients with acute cerebral infarction, including 30 males, 35 females are from the department of neurology of Tai Zhou Hospital, whose ages range from 36 to 76 and the average age is 63.27 ±10.15. forty-five healthy persons including 20 males, 25 females are selected from physical examination and become the control group, whose ages range from 35 to 69 and the average age is 55.96±10.21. Serum MMP-9 level was measured by means of ELISA( enzyme-linked immunosorbent assay ). At the same time. Genotype was determined by PCR-RFLP ( polymerase chain reaction-restriction fragment length Polymorphism ) for the common C-1562T functional promoter polymorphism of the MMP-9 gene. The serum MMP-9 level and genotype frequencies of the MMP-9 gene between the patients and the control group have been analyzed.Results: The genotype frequencies of the MMP-9 gene C-1562T polymorphism of the two groups were in Hardy-Weinberg equilibrium.The results of individual polymorphisms analysis showed that the frequencies of C/T and T/T genotypes in the C-1562T polyporphismin were of no significant difference between the patients group with CI (15.4%) and the control group(13.3%). The frequencies of-1562T allele were of no statistical difference between the CI group(7.7%) and the control group(7.8%). But serum levels of MMP-9 in CI patients group (124.36±102.61 ng/mL )were significantly higher than in the control group( 10.38 ± 4.68 ng/mL ). And the level of MMP-9 was unrelated to NIHSS.Conclusion: Serum level of MMP-9 obviously increased after ischemic stroke in 48 hours . but the level of MMP-9 was unrelated to NIHSS. genetic polymorphism in MMP-9 promoter( C-1562T )has no definite relationship with MMP-9 genetic expression and CI in the Han population of China. Therefore, the relationship between genetic polymorphism in MMP-9 promoter( C-1562T )and ischemic stroke needs further investigation.