A new redox-dependent mechanism of MMP-1 activity control comprising reduced low-molecular-weight thiols and oxidizing radicals

Abstract

Matrix metalloproteinases (MMPs), a family of zinc-dependent proteinases, participate in remodeling and degradation of the extracellular matrix proteins. The activity of MMPs is thought to be predominately posttranslationally regulated via proteolytic activation of precursor zymogens or via their naturally occurring endogenous inhibitors. Here, using recombinant MMP-1, we investigated new redox-dependent mechanisms of proteinase activity regulation by low-molecular-weight thiols. We find that glutathione (GSH), cysteine, homocysteine, and N-acetylcysteine at physiological concentrations competitively reduce MMP-1 activity up to 75% with an efficiency of cysteine > or = GSH > homocysteine > N-acetylcysteine. In contrast, S-derivatized thiols completely lack this inhibitory activity. Interestingly, the competitive GSH-mediated inhibition of MMP-1-activity can be fully reversed abrogated by oxidizing radicals like (*)NO(2) or Trolox radicals, here generated by UVA irradiation of nitrite or Trolox, two relevant agents in human skin physiology. This redox-dependent reactivation of the inactive GSH-MMP-1-complex comprises GSH oxidation and is significantly inhibited in the presence of ascorbic acid, an effective (*)NO(2) and Trolox radical scavenger. We here offer a new concept of redox-sensitive control of MMP-1 activity based on the inhibitory effect of reduced thiols and reactivation by a mechanism comprising derivatization or oxidation of the MMP-1-bound inhibitory-acting thiol.

Enhancement of Radiation Response in Breast Cancer Stem Cells by Inhibition of Thioredoxin- and Glutathione-Dependent Metabolism

“…(19, 20) Figure 5 shows that the combination of Au+BSO in the presence and absence of IR significantly decreased MDA-MB-231 cells’ ability to migrate through both control membranes (Figure 5A) as well as Matrigel basement membranes (Figure 5B). Furthermore, the ability of Au+BSO to inhibit invasion and migration was abrogated by treatment with NAC, supporting the conclusion that this biological effect was caused by compromised GSH- and Trx-dependent thiol metabolism (Figure 5A,B) Notably, treating with either Au or BSO before IR did not significantly affect migration through the control membrane (Figure 5A) but did significantly decrease the cells’ ability to invade the Matrigel membrane (Figure 5B) which is consistent with previous studies.…”

Role of Oxidative Stress and the Microenvironment in Breast Cancer Development and Progression

“…Not only collagen deposition but also collagen degradation is required for the physiologic remodeling of connective tissue during breast cancer growth, development, and cancer cell invasion. Secreted metalloproteinases (MMP) such as MMP-2, MMP-3, and MMP-9 increase extracellular matrix turnover and are themselves activated by oxidative stress (Fu et al, 2001; Koch et al, 2009; Provenzano et al, 2008; Radisky et al, 2005). Additionally secreted transforming growth factor β (TGFβ), insulin-like growth factor (IGF), platelet-derived growth factor (PDGF), fibroblast growth factor 2, and stromal-derived factor 1 (SDF1) are able to activate fibroblasts and increase cancer cell proliferation (Sappino et al, 1988).…”

Redox-control of matrix metalloproteinase-1: A critical link between free radicals, matrix remodeling and degenerative disease

“…Oxidative stress has been shown to modulate the thiol interaction between the prodomain and catalytic domain of MMP-7 leading to its activation. Work by Suschek and coworkers indicates that small molecular weight thiols including glutathione restrict MMP-1 activity and oxidation of the MMP-1 bound inhibitory thiol is required for its activation (Koch et al 2009). …”