• BMB Reports
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• v.53 no.6
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• pp.323-328
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• 2020

Matrix metalloproteinase 1 (MMP-1), a calcium-dependent zinccontaining collagenase, is involved in the initial degradation of native fibrillar collagen. Tissue necrosis factor-alpha (TNFα) is a pro-inflammatory cytokine that is rapidly produced by dermal fibroblasts, monocytes/macrophages, and keratinocytes and regulates inflammation and damaged-tissue remodeling. MMP-1 is induced by TNFα and plays a critical role in tissue remodeling and skin aging processes. However, the regulation of the MMP1 gene by TNFα is not fully understood. We aimed to find additional cis-acting elements involved in the regulation of TNFα-induced MMP1 gene transcription in addition to the nuclear factor-kappa B (NF-κB) and activator protein 1 (AP1) sites. Assessments of the 5'-regulatory region of the MMP1 gene, using a series of deletion constructs, revealed the requirement of the early growth response protein 1 (EGR-1)-binding sequence (EBS) in the proximal region for proper transcription by TNFα. Ectopic expression of EGR-1, a zinc-finger transcription factor that binds to G-C rich sequences, stimulated MMP1 promoter activity. The silencing of EGR-1 by RNA interference reduced TNFα-induced MMP-1 expression. EGR-1 directly binds to the proximal region and transactivates the MMP1 gene promoter. Mutation of the EBS within the MMP1 promoter abolished EGR-1-mediated MMP-1 promoter activation. These data suggest that EGR-1 is required for TNFα-induced MMP1 transcriptional activation. In addition, we found that all three MAPKs, ERK1/2, JNK, and p38 kinase, mediate TNFα-induced MMP-1 expression via EGR-1 upregulation. These results suggest that EGR-1 may represent a good target for the development of pharmaceutical agents to reduce inflammation-induced MMP-1 expression.

• BMB Reports
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• v.53 no.12
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• pp.628-633
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• 2020

WNT11 is a member of the non-canonical Wnt family and plays a crucial role in tumor progression. However, the regulatory mechanisms underlying WNT11 expression are unclear. Tumor necrosis factor-alpha (TNFα) is a major inflammatory cytokine produced in the tumor microenvironment and contributes to processes associated with tumor progression, such as tumor invasion and metastasis. By using site-directed mutagenesis and introducing a serial deletion in the 5'-regulatory region of WNT11, we observed that TNFα activates the early growth response 1 (EGR1)-binding sequence (EBS) in the proximal region of WNT11 and that the transcription factor EGR1 is necessary for the TNFα-induced transcription of WNT11. EGR1 bound directly to the EBSs within the proximal 5'-regulatory region of WNT11 and ectopic expression of EGR1 stimulated WNT11 promoter activity, whereas the knockdown of EGR1 expression by RNA interference reduced TNFα-induced WNT11 expression in T47D breast cancer cells. We also observed that mitogen-activated protein kinases (MAPK), extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 kinase mediated TNFα-induced transcription of WNT11 via EGR1. Our results suggest that EGR1 directly targets WNT11 in response to TNFα stimulation in breast cancer cells.