Functional Promoter Polymorphisms of MMP-2 C-735T and MMP-9 C-1562T and Their Synergism with MMP-7 A-181G in Multiple Sclerosis

Abstract

ABSTRACTMultiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system. Matrix metalloproteinases (MMPs) play an important role in breakdown of blood–brain barrier, transmigration, and invasion of immune cells and formation of MS lesions. The aim of present study was to investigate the influence of MMP-2 C-735T and MMP-9 C-1562T variants and their synergism with MMP-7 A-181G on susceptibility to MS. In a case–control study 125 MS patients and 235 healthy individuals from Western Iran were investigated. The various genotypes of MMP-2, MMP-9, and MMP-7 were detected using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). In females the presence of MMP-2 C allele was associated with an increased risk of MS (OR = 1.69, p = 0.041). No significant difference was detected between the frequency of MMP-9 T allele in MS patients (8.2%) and controls (12.8%, p = 0.068). The concomitant presence of both MMP-2 C and MMP-7 G alleles was associated with 1.82-fold increased risk of MS (p = 0.002). Also, a synergism was detected between MMP-9 C and MMP-7 G alleles that elevated the risk of MS by 1.5-times (p = 0.035). The presence of haplotype MMP-9 T, MMP-7 G, and MMP-2 C (TGC) compared to haplotype CAG increased the risk of MS by 3.13-fold (p = 0.16). The present study suggests that gene–gene interactions and variants of more genes instead of single gene might play a role in susceptibility to MS. We indicated that synergism between variants of MMP-2, MMP-7, and MMP-9 genes might increase the risk of MS.