TNF-α stimulates activation of pro-MMP2 in human skin through NF-κB mediated induction of MT1-MMP

Abstract

Tumor necrosis factor-alpha (TNF-(alpha)) is an important mediator during the inflammatory phase of wound healing. Excessive amounts of pro-inflammatory cytokines such as TNF-(alpha) are associated with inflammatory diseases including chronic wounds. Matrix metalloproteinases (MMPs) are involved in matrix re-modeling during wound healing, angiogenesis and tumor metastasis. As with pro-inflammatory cytokines, high levels of MMPs have been found in inflammatory states such as chronic wounds. In this report we relate these two phenomena. TNF-(alpha) stimulates secretion of active MMP-2, a type IV collagenase, in organ-cultured full-thickness human skin. This suggests a mechanism whereby excess inflammation affects normal wound healing. To investigate this observation at the cellular and molecular levels, we examined TNF-(alpha) mediated activation of pro-MMP-2, induction of MT1-MMP, and the intracellular signaling pathways that regulate the proteinase in isolated human dermal fibroblasts. We found that TNF-(alpha) substantially promoted activation of pro-MMP-2 in dermal fibroblasts embedded in type-I collagen. In marked contrast, collagen or TNF-(alpha) individually had little influence on the fibroblast-mediated pro-MMP-2 activation. One well-characterized mechanism for pro-MMP-2 activation is through a membrane type matrix metalloproteinase, such as MT1-MMP. We report that TNF-(alpha) significantly induced MT1-MMP at the mRNA and protein levels when the dermal fibroblasts were grown in collagen. Although the intracellular signaling pathway regulating mt1-mmp gene expression is still obscure, both TNF-(alpha) and collagen activate the NF-(kappa)B pathway. In this report we provide three sets of evidence to support a hypothesis that activation of NF-(kappa)B is essential to induce MT1-MMP expression in fibroblasts after TNF-(alpha) exposure. First, SN50, a peptide inhibitor for NF-(kappa)B nuclear translocation, simultaneously blocked the TNF-(alpha) and collagen mediated MT1-MMP induction and pro-MMP-2 activation. Secondly, TNF-(alpha) induced I(kappa)B to breakdown in fibroblasts within the collagen lattice, a critical step leading to NF-(kappa)B activation. Lastly, a consensus binding site for p65 NF-(kappa)B (TGGAGCTTCC) was found in the 5′-flanking region of human mt1-mmp gene. Based on these results and previous reports, we propose a model to explain TNF-(alpha) activation of MMP-2 in human skin. Activation of NF(kappa)B signaling in fibroblasts embedded in collagen induces mt1-mmp gene expression, which subsequently activates the pro-MMP-2. The findings provide a specific mechanism whereby TNF-(alpha) may affect matrix remodeling during wound healing and other physiological and pathological processes.

Antimetastatic Effects of Curcumin in Oral and Gastrointestinal Cancers

“…MMPs play pivotal functions in various tumor development features via affecting numerous biological processes. These features include activation of growth factor (Egeblad and Werb, 2002), tumor growth, induction of invasiveness, tumor-related inflammation, revascularization, and metastasis (Han et al, 2001;Philip et al, 2001). Hence, controlling expression levels of MMPs and suppression of its activation can be considered an optimal strategy for the prevention of cancer development.…”

“…SDF-1a/CXCR4 axismediated cell migration needs the activation of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) in breast cancer cells (Lee et al, 2004). Numerous investigations demonstrated that hormones, growth factors, and cytokines stimulated the MMP-2 expression via nuclear factor-kappaB (NF-kB) activation (Han et al, 2001;Philip et al, 2004). NF-kB transcription factor constitutive activation in EC has been related to metastatic ability and chemotherapy resistance (Izzo et al, 2006).…”

The Stimulating Effect of Rosmarinic Acid and Extracts from Rosemary and Lemon Balm on Collagen Type I Biosynthesis in Osteogenesis Imperfecta Type I Skin Fibroblasts

“…Their secretion is stimulated by oxidative stress, UV radiation, and cytokines and they play an important role in in wound healing, skeletal growth, and remodeling as well as various pathophysiological processes, such as photoaging, inflammation, angiogenesis, and cancer [49]. In skin fibroblasts, MMPs are secreted in a latent form and the active forms appear in the medium after culturing for 72-96 h [64]. In our study to test the activity of MMP-1, -2, and -9 after 24 h of cell culture, MMPs were activated with APMA.…”

The Extracellular Matrix in Skin Inflammation and Infection

“…Both strategies can potentially change the force load on the matrix, either by upregulating cell binding to the matrix, inducing filopodia, or by increasing or decreasing pulling forces exerted by the cells through F-actin modifications (Taylor et al, 2011; Table 3). Proinflammatory cytokines are secreted en masse by activated immune cells upon virus infection resulting in increased activation of MMPs and altered ECM deposition (Han et al, 2001). As such, viruses can indirectly induce ECM remodeling by increasing collagenase expression in tissues.…”