Age- and Gender-Dependent Changes in Connective Tissue Remodeling: Physiological Differences in Circulating MMP-3, MMP-10, TIMP-1 and TIMP-2 Level

BACKGROUND: the mechanisms which cause age-dependent remodeling of connective tissue are still not fully understood. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) constitute an important proteolytic pathway affecting physiological matrix remodeling. OBJECTIVE: the way in which changes in the extracellular matrix metabolism during the ageing process influence the level of circulating MMP-3 and MMP-10, as well as their tissue inhibitors TIMP-1 and TIMP-2, in a healthy population was investigated in this study. METHODS: blood samples were taken from 81 healthy individuals aged 6-62 years and measured for MMP-3, MMP-10, TIMP-1 and TIMP-2 levels using enzyme-linked immunosorbent assays. Polyacrylamide gel electrophoresis followed by Western immunoblotting allowed for the detection of pro- and active forms of both MMPs. RESULTS: Serum MMP-3 and TIMP-1 values were positively correlated with age (r = 0.44, p = 0.00001 and r = 0.28, p = 0.012, respectively). A contrary tendency was found for MMP-10 and TIMP-2 serum levels. A strong age-related decrease in MMP-10 (-0.53; p = 0.000) and TIMP-2 (-0.52; p = 0.000) was noticed in our study. Gender was a significant factor modifying MMP/TIMP potential, except for the MMP-10 level. CONCLUSIONS: the data presented indicate that changes in MMP/TIMP balance occur in physiological ageing. Moreover, these findings highlight the necessity of utilizing age- and sex-matched values for analysis of MMPs and TIMPs in the pathological conditions.