Kon A, Vindevoghel L, Kouba D J, Fujimura Y, Uitto J, Mauviel A
Department of Dermatology and Cutaneous Biology, Jefferson Institute of Molecular Medicine, Jefferson Medical College, Philadelphia, Pennsylvania, USA.
Oncogene. 1999 Mar 11;18(10):1837-44. doi: 10.1038/sj.onc.1202495.
We have previously demonstrated that transforming growth factor-beta (TGF-beta) and pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha) or interleukin-1beta, synergistically enhance the expression of type VII collagen gene (COL7A1) in human dermal fibroblasts in culture (Mauviel et al., 1994). Recently, we identified a SMAD-containing complex, rapidly induced by TGF-beta and binding the region [-496/-444] of the COL7A1 promoter, responsible for COL7A1 gene transactivation (Vindevoghel et al., 1998a). In this report, we demonstrate that TGF-beta and TNF-alpha response elements are distinct entities within the COL7A1 promoter. In particular, we demonstrate that the TNF-alpha effect is mediated by NF-kappaB1/RelA (p50/p65) and RelA/RelA (p65/p65) NF-kappaB complexes binding the TNF-alpha response element (TaRE) located in the region [-252/-230], with RelA acting as the transcriptional activator. Finally, we provide definitive evidence for the role of both TGF-beta and TNF-alpha response elements as enhancer sequences, functioning in the context of a heterologous promoter in an additive manner in response to TGF-beta and TNF-alpha. This study provides the first identification of a functional interaction between the two immediate-early transcription factors, SMAD and NF-kappaB, to activate the expression of an extracellular matrix-related gene, COL7A1.
我们先前已证明，转化生长因子-β（TGF-β）与促炎细胞因子，如肿瘤坏死因子-α（TNF-α）或白细胞介素-1β，可协同增强培养的人皮肤成纤维细胞中VII型胶原基因（COL7A1）的表达（Mauviel等人，1994年）。最近，我们鉴定出一种含SMAD的复合物，它由TGF-β快速诱导并结合COL7A1启动子的[-496 / -444]区域，负责COL7A1基因的反式激活（Vindevoghel等人，1998a）。在本报告中，我们证明TGF-β和TNF-α反应元件是COL7A1启动子内不同的实体。特别是，我们证明TNF-α的作用是由结合位于[-252 / -230]区域的TNF-α反应元件（TaRE）的NF-κB1/RelA（p50 / p65）和RelA/RelA（p65 / p65）NF-κB复合物介导的，其中RelA作为转录激活因子。最后，我们提供了确凿的证据，证明TGF-β和TNF-α反应元件作为增强子序列的作用，它们在异源启动子的背景下以加性方式响应TGF-β和TNF-α发挥作用。本研究首次鉴定了两种早期即刻转录因子SMAD和NF-κB之间的功能性相互作用，以激活细胞外基质相关基因COL7A1的表达。
