Nitric oxide regulates matrix metalloproteinase-9 activity by guanylyl-cyclase-dependent and -independent pathways

Abstract

Matrix metalloproteinases (MMPs) are of central importance in the proteolytic remodeling of matrix and the generation of biologically active molecules. MMPs are distinguished by a conserved catalytic domain containing a zinc ion, as well as a prodomain that regulates enzyme activation by modulation of a cysteine residue within that domain. Because nitric oxide (NO) and derived reactive nitrogen species target zinc ions and cysteine thiols, we assessed the ability of NO to regulate MMPs. A dose-dependent, biphasic regulatory effect of NO on the activity of MMPs (MMP-9, -1, and -13) secreted from murine macrophages was observed. Low exogenous NO perturbed MMP/tissue inhibitor of metalloproteinase (TIMP)-1 levels by enhancing MMP activity and suppressing the endogenous inhibitor TIMP-1. This was cGMP-dependent, as confirmed by the cGMP analog 8-bromo-cGMP, as well as by the NO-soluble guanylyl cyclase-cGMP signaling inhibitor thrombospondin-1. Exposure of purified latent MMP-9 to exogenous NO demonstrated a concentration-dependent activation and inactivation of the enzyme, which occurred at higher NO flux. These chemical reactions occurred at concentrations similar to that of activated macrophages. Importantly, these results suggest that NO regulation of MMP-9 secreted from macrophages may occur chemically by reactive nitrogen species-mediated protein modification, biologically through soluble guanylyl-cyclase-dependent modulation of the MMP-9/TIMP-1 balance, or proteolytically through regulation of MMP-1 and -13, which can cleave the prodomain of MMP-9. Furthermore, when applied in a wound model, conditioned media exhibiting peak MMP activity increased vascular cell migration that was MMP-9-dependent, suggesting that MMP-9 is a key physiologic mediator of the effects of NO in this model. tissue inhibitor of metalloproteinase-1 ͉ thrombospondin-1

Nitric Oxide Regulation of MMP-9 Activation and Its Relationship to Modifications of the Cysteine Switch

“…Recently, a similar inhibition of MMP-9 activity by high concentrations of SPER-NO was reported, but a mechanism for inhibition was not investigated or suggested (28). Although MMP-9 inhibition was observed using relatively high concentrations of DETA-NO (500-1000 µM) or SPER-NO (100 µM), these concentrations of NO donors produce sub-micromolar steady state NO levels that are reflective of NO production by, for example, activated macrophages (22,28), and may thus be relevant to inflammatory conditions. Since MMPs are subject to inactivation by oxidative mechanisms (7,9,34), it may not be surprising that high concentrations of NO or RNS may similarly inactivate MMPs.…”

The effects of nitric oxide on the immune system during Trypanosoma cruzi infection

“…The migration of inflammatory cells may also be affected by the chemical modifications of matrix metalloproteinases (MMPs) (Ridnour et al 2007). Recently, NO may also affect lymphocyte migration by altering cell motility.…”

Silicon‐based quantum dots induce inflammation in human lung cells and disrupt extracellular matrix homeostasis

“…Generally, ROS activate MMPs by modifying the cysteine residue that stabilizes the inactive structure [59], although some studies supporting our results revealed a reduction of the activity of MMPs by tryptophan oxidation in the catalytic domain by ROS to restrain proteolytic activity during inflammation [60,61] or as a result of excessive protein oxidation, which led to protein degradation and altered the biological functions of MMPs. Because latent MMP-9 is proteolytically activated by MMP-1, the suppression of MMP-1 activity can be responsible for the decrease of MMP-9 activity together with the increased expression of TIMP-1 and high levels of NO [62]. Because the ECM plays a pivotal role in the cytoskeletal filament assembly, the changes induced by Si/SiO 2 QDs on MMPs expression and activity correlate with the alteration of the actin cytoskeleton [63].…”