Correlation of MMP-9 gene polymorphisms with aneurysmal subarachnoid hemorrhage and its prognosis

Background: Aneurysmal subarachnoid hemorrhage (aSAH)-associated gene polymorphism is of great significance for the accurate diagnosis and individualized treatment of aSAH. This study aims to investigate the expression of matrix metalloproteinase-9 (MMP-9) gene in the peripheral blood of patients with aneurysmal subarachnoid hemorrhage (aSAH) and explore the correlations of MMP-9 polymorphisms with the onset and prognosis of the disease. Methods: A total of 80 aSAH patients (aSAH group) and 24 healthy (control group) people receiving physical examination were enrolled in the study. Western blotting was applied to detect the expression of MMP-9 gene in the peripheral blood in aSAH patients and healthy people. The genotyping of single nucleotide polymorphisms (rs42512, rs56212 and rs61221) in the promoter region of MMP-9 gene was analyzed by means of conformation-difference gel electrophoresis. Chi-square test was applied to examine the applicability of the distribution frequency of MMP-9 genotypes with genetic equilibrium law. The correlations of MMP-9 alleles and gene polymorphisms with the onset and prognosis of aSAH were determined. Results: The expression of MMP-9 protein in aSAH group was significantly higher than that in control group (P<0.05). The Hardy-Weinberg equilibrium analysis showed that MMP-9 gene polymorphisms were in agreement with the genetic equilibrium law. According to the results of genetic association analysis, only the polymorphism rs42512 and its alleles were significantly correlated with the onset and prognosis of aSAH (P<0.05). However, polymorphisms rs56212 and rs61221 and their alleles had no association with the onset and prognosis of aSAH (P>0.05). Conclusion: The polymorphism rs42512 in the promoter region of MMP-9 gene is related to the onset of aSAH, which provides further evidence for the diagnosis of aSAH.