TNF-alpha stimulates activation of pro-MMP2 in human skin through NF-(kappa)B mediated induction of MT1-MMP.
TNF-alpha stimulates activation of pro-MMP2 in human skin through NF-(kappa)B mediated induction of MT1-MMP.
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DOI：
10.1242/jcs.114.1.131
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发表时间：
2001
影响因子：
4
通讯作者：
Yuanping Han;T. Tuan;Huayang Wu;M. Hughes;W. Garner
中科院分区：
文献类型：
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作者：
Yuanping Han;T. Tuan;Huayang Wu;M. Hughes;W. Garner
肿瘤坏死因子- α (TNF-(α))是伤口愈合炎症期的重要介质。过量的促炎细胞因子如TNF-(α)与炎性疾病包括慢性伤口有关。基质金属蛋白酶（MMPs）在伤口愈合、血管生成和肿瘤转移过程中参与基质重塑。与促炎细胞因子一样，在慢性伤口等炎症状态中也发现了高水平的MMPs。在本报告中，我们把这两种现象联系起来。在器官培养的全层人皮肤中，TNF-(α)刺激活性MMP-2（一种IV型胶原酶）的分泌。这表明了过度炎症影响正常伤口愈合的机制。为了在细胞和分子水平上研究这一观察结果，我们在分离的人真皮成纤维细胞中检测了TNF-(α)介导的前mmp -2的激活、MT1-MMP的诱导以及调节蛋白酶的细胞内信号通路。我们发现TNF-(α)显著促进了嵌入i型胶原的真皮成纤维细胞中前mmp -2的活化。与之形成鲜明对比的是，胶原蛋白或TNF-(α)单独对成纤维细胞介导的前mmp -2活化影响不大。mmp -2激活的一个很好的机制是通过膜型基质金属蛋白酶，如MT1-MMP。我们报道了当真皮成纤维细胞在胶原中生长时，TNF-(α)在mRNA和蛋白水平上显著诱导MT1-MMP。虽然调节mt1-mmp基因表达的细胞内信号通路尚不清楚，但TNF-(α)和胶原蛋白均可激活NF-(kappa)B通路。在本报告中，我们提供了三组证据来支持一个假设，即TNF-(α)暴露后，NF-(kappa)B的激活对于诱导成纤维细胞中MT1-MMP的表达至关重要。首先，SN50，一种NF-(kappa)B核易位的肽抑制剂，同时阻断TNF-(α)和胶原介导的MT1-MMP诱导和前mmp -2激活。其次，TNF-(α)诱导I(kappa)B在胶原晶格内的成纤维细胞中分解，这是导致NF-(kappa)B激活的关键步骤。最后，在人类mt1-mmp基因的5'侧区发现了p65 NF-(kappa)B （TGGAGCTTCC）的一致结合位点。基于这些结果和先前的报告，我们提出了一个模型来解释人类皮肤中TNF-(α)激活MMP-2。嵌入胶原的成纤维细胞中NF(kappa)B信号的激活诱导mt1-mmp基因表达，随后激活前mmp -2。这些发现提供了TNF-(α)在伤口愈合和其他生理和病理过程中影响基质重塑的特定机制。
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.