The inhibition of MAPK pathway is correlated with down-regulation of MMP-9 secretion induced by TNF-α in human keratinocytes
The inhibition of MAPK pathway is correlated with down-regulation of MMP-9 secretion induced by TNF-α in human keratinocytes
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DOI：
10.1016/s0014-4827(03)00293-3
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发表时间：
2003-10-15
影响因子：
3.7
通讯作者：
Serres, M
中科院分区：
文献类型：
--
作者：
Holvoet, S;Vincent, C;Serres, M
MMP-9（92 kDa）是能够降解胶原IV的主要明胶酶，由积极参与伤口愈合或肿瘤发生的角质形成细胞分泌。由于癌症的侵袭性表型依赖于MMP-9表达，因此精确表征TNF-α激活的哪些信号转导途径参与TNF-α诱导的MMP-9上调似乎是有意义的。在HaCaT细胞中，MMP-9的激活发生在转录水平。使用Ras、Raf、MEK 1/2和Erk 1/2级联的特异性抑制剂抑制MAPK通路与MMP-9活性的显著抑制相关，如通过基因和蛋白质表达测定的。通过在EMSA中检测到的显著AP-1活化证实了经由TNF-α的MAPK途径活化。在我们的实验条件下，p38 MAPK和SAPK/JNK通路没有被激活。调节MMP-9的其他MMP的基因和蛋白质表达，如MMP-1和MMP-13，也被TNF-α上调，并被UO 126抑制，这提供了MAPK途径在角质形成细胞调节MMP-9分泌中起重要作用的证据。由于已知TNF-α是NF-κ B通路的主要激活剂，因此研究了喜树碱和咖啡酸的作用，例如TNF-α喜树碱上调MMP-9活性，而咖啡酸仅弱抑制TNF-α诱导的MMP-9激活。然而，如免疫染色数据所示，在TNF-α处理后，NF-κ B被激活，检测到p50和p65 NF-κ B亚基的核染色和更高的Western印迹表达。对于TNF-α处理的细胞，在EMSA中也检测到更高的特异性信号。(C)2003年爱思唯尔公司All rights reserved.
MMP-9 (92 kDa) is the major gelatinase able to degrade collagen IV, secreted by keratinocytes that are actively involved in wound-healing or tumorigenesis. Since the invasive phenotype of cancers is dependent on MMP-9 expression, it appeared of interest to precisely characterize which signal transduction pathways activated by TNF-alpha are involved in MMP-9 up-regulation induced by TNF-a. In HaCaT cells, activation of MMP-9 occurs at the transcriptional level. Inhibition of the MAPK pathway using specific inhibitors of the Ras, Raf, MEK1/2, and Erk1/2 cascade was correlated with a marked inhibition of MMP-9 activity, as determined by gene and protein expression. MAPK pathway activation via TNF-alpha was confirmed by marked AP-1 activation detected in EMSA. Under our experimental conditions, p38 MAPK and SAPK/JNK pathways were not activated. Gene and protein expression of other MMPs that regulate MMP-9, such as MMP-1 and MMP-13, were also up-regulated by TNF-alpha and inhibited by UO126, providing evidence that the MAPK pathway plays a fundamental role in the regulation of MMP-9 secretion by keratinocytes. As TNF-alpha is known to be a main activator of NF-kappaB pathway, the effects of campthothecin and caffeic acid were investigated, such as, TNF-alpha campthothecin up-regulated MMP-9 activity but caffeic acid only weakly inhibited MMP-9 activation induced by TNF-alpha. However, NF-kappaB is activated as shown from immunostaining data, a nuclear staining and higher Western blotting expression of p50 and p65 NF-kappaB subunits were detected, after TNF-alpha treatment. A higher specific signal was also detected in EMSA for TNF-alpha-treated cells. (C) 2003 Elsevier Inc. All rights reserved.