Increased expression ratio of matrix metalloproteinase-9 (MMP9) and tissue inhibitor of matrix metalloproteinase (TIMP-1) RNA levels in Iranian multiple sclerosis patients

Abstract

OBJECTIVES:

Multiple sclerosis (MS) is an autoimmune disease involving the central nervous system (CNS) with unknown immunopathogenic mechanisms. Matrix metalloproteinase-9 (MMP-9) facilitates T-cell migration into the CNS while the tissue inhibitor matrix metalloproteinase-1 (TIMP-1) inhibits MMP-9 actions. The aim of this study was to evaluate the expression of TIMP-1 RNA and MMP-9/TIMP-1 RNA ratio in blood cells of Iranian patients with relapsing-remitting multiple sclerosis (RRMS) treated with IFNb.

MATERIAL AND METHODS:

The study compared the expression level of TIMP-1 gene in RRMS samples with normal individuals in Iran and the results were compared using a ratio of MMP-9 to TIMP-1. All patients were HLA-DRB1*15 negative and were responders to interferon-beta with a normal vitamin D level.

RESULTS:

The RRMS patients manifested a lower expression level of TIMP-1 RNA than their normal counterparts although the result was not significant (P= 0.06). Also, the ratio of MMP-9 to TIMP-1 RNA increased significantly (P= 0.009). There was no linear correlation between TIMP-1 expression level and risk of Expanded Disability Status Scale of Kurtzke(EDSS); nor was there any significant correlation between expression status of TIMP-1 and duration of the disease. Although there was no significant decrease in TIMP-1 expression level, the MMP-9/TIMP-1 RNA ratio in RRMS was significantly higher than normal subjects.

CONCLUSION:

Further studies are recommended to compare MMP-9/TIMP-1 RNA ratio in patients before and after taking IFN-beta in order to find out if MMP-9/TIMP-1 RNA ratio can function as a proper marker of the bio efficacy of IFN-beta treatment of MS.