Division of Oral Biotechnology, Center for Dental Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Hugstetterstr. 55, 79106, Freiburg, Germany.
Faculty of Engineering, University of Freiburg, Georges-Köhler-Allee 101, 79110, Freiburg, Germany.
J Biomed Mater Res A. 2019 Mar;107(3):663-677. doi: 10.1002/jbm.a.36585. Epub 2018 Dec 10.
In biomaterials research, biomechanics which support tissue regeneration steadily gains of importance. Hence, we have previously shown that gelatin-based electrospun nonwoven mats (NWMs) with a distinct modulus of elasticity (3.2 kPa) promotes epithelial morphogenesis. Since molecular mechanisms of this morphogenesis are still unknown, the present study aims at identifying molecules, involved herein. Epithelia established on the NMWs showed persistence of the activated state of the epidermal growth factor receptor (EGF-R), phosphorylated at the src-specific tyrosine 845 (EGF-R ) throughout the observation period of 10 days. To elucidate whether the observed morphogenesis mechanistically involves EGF-R signaling, we inhibited EGF-R, by employing the EGF-R specific inhibitor Gefitinib (IRESSA®). Gefitinib administration yielded a reduced expression of the β1 integrin subunit, a well-known cell-matrix interaction receptor, concomitant with downregulation of p42/44 ERK1/2 MAP-kinase activity. To elucidate whether the observed downregulation of β1 is EGF-R -dependent or emerging from ERK1/2 signaling, we exposed epithelia, grown on the NWMs, with the ERK1/2-directed inhibitor U0126. In the absence of Gefitinib, inhibition of p42/44 MAP-kinase activity resulted in decreased β1 integrin protein levels, thus indicating that β1 expression is dependent on ERK1/2 and not EGF-R . Our results showed the first time that an EGF-R-β1 integrin-signaling axis, including ERK1/2, promotes NWM-elasticity-based epithelial morphogenesis. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 663-677, 2019.
在生物材料研究中，支持组织再生的生物力学逐渐变得越来越重要。因此，我们之前已经表明，具有明显弹性模量（3.2 kPa）的基于明胶的静电纺非织造毡（NWMs）可促进上皮形态发生。由于这种形态发生的分子机制尚不清楚，因此本研究旨在鉴定涉及的分子。在 NMW 上建立的上皮细胞在整个 10 天的观察期内显示出表皮生长因子受体（EGF-R）的激活状态持续存在，该受体在 src 特异性酪氨酸 845 处被磷酸化（EGF-R）。为了阐明观察到的形态发生是否在机制上涉及 EGF-R 信号传导，我们通过使用 EGF-R 特异性抑制剂吉非替尼（IRESSA®）来抑制 EGF-R。吉非替尼给药导致众所周知的细胞-基质相互作用受体β1 整联蛋白亚基的表达减少，同时 p42/44 ERK1/2 MAP-激酶活性下调。为了阐明观察到的β1 下调是否依赖于 EGF-R 或源自 ERK1/2 信号传导，我们用 ERK1/2 定向抑制剂 U0126 暴露于 NWMs 上生长的上皮细胞。在没有 Gefitinib 的情况下，抑制 p42/44 MAP-激酶活性会导致β1 整联蛋白蛋白水平降低，这表明β1 表达依赖于 ERK1/2 而不是 EGF-R。我们的结果首次表明，EGF-R-β1 整联蛋白信号轴，包括 ERK1/2，可促进基于 NWM 弹性的上皮形态发生。 © 2018 Wiley Periodicals，Inc. J Biomed Mater Res Part A：107A：663-677，2019。
