Plasma membrane-mediated non-genomic effects of T4, T3 and thyroid hormone metabolite tetrac on different aspects of mesenchymal stem cell biology and their signaling pathways

T4、T3 和甲状腺激素代谢物 tetrac 的质膜介导的非基因组效应对间充质干细胞生物学及其信号通路的不同方面

• 批准号: 221140710
• 负责人: Professor Dr. Peter Jon Nelson
• 金额: --
• 依托单位: Medizinische Klinik und Poliklinik IV
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/221140710?language=en
• 关键词: Plasma; membrane; mediated; non; genomic

In the recent years we and others have shown that mesenchymal stem cells (MSCs) selectively home to sites of injury and play an important role in tissue repair, wound healing and cancer through differentiation and the release of proangiogenic factors. In the last funding period we demonstrated, for the first time, that T4 and T3 are important stimulators of MSC differentiation in fibroblast-/pericyte-like cells, and have direct stimulatory effects on MSC migration, invasion and recruitment. These effects were shown to be mediated through non-genomic mechanisms via avb3 by their tetrac inhibition. One of the possible molecular mechanisms for this observation is T4/T3-mediated stimulation of the hypoxia response network in MSCs which was also demonstrated in our past funding period. As a logical consequence of our past studies, in the next funding period we will analyze in more detail the mechanistic basis for the non-genomic avb3-mediated effects of T4, T3 and tetrac on the migration of MSCs and MSC-mediated angiogenic effects with a special emphasis on characterization of the signaling pathways involved. For this purpose we will analyze the effects of T4, T3 and tetrac on 1) the expression of MSC cell surface markers, integrins and receptors that are associated with MSC migration, 2) the secretion of angiogenic factors by MSCs and their effect on endothelial cell tube formation. Based on preliminary data by others and our own group, the PI3K/Akt, MAPK and canonical Wnt pathways are logical candidates for further analysis as to their involvement in avb3-mediated non-genomic effects of T4, T3 and tetrac in MSC biology. Therefore, in the current proposal these pathways will be investigated by analysis of downstream targets after treatment of MSCs with T4, T3 in the presence or absence of tetrac, and the effect on MSC migration and invasion after application of specific inhibitors of these pathways. In addition, the activation status of the canonical Wnt pathway as well as two central angiogenesis-related pathways, Tie-2 and VEGF signaling pathways, will be assessed by using pathway-responsive reporter assays in vitro and in vivo using NIS as a reporter gene making use of our longstanding expertise in the application of NIS as theranostic gene. Based on the strong analogies between the process of wound healing and tumor stroma formation, the liver cancer xenograft mouse model established in our previous studies will be used as a robust model of chronic wound/tissue repair. These studies will significantly enhance our understanding of the critical role of thyroid hormones T4 and T3 as well as tetrac in regulation of MSC biology in the context of chronic wound/tissue repair. At the same time, our studies will expand our understanding of the evolving role of integrin avb3 as mediator of thyroid hormone action and its therapeutic implications.

近年来，我们和其他人已经证明间充质干细胞（MSC）选择性地归巢于损伤部位，并通过分化和释放促血管生成因子在组织修复、伤口愈合和癌症中发挥重要作用。在上一个资助期间，我们首次证明T4和T3是成纤维细胞/周细胞样细胞中MSC分化的重要刺激剂，并对MSC迁移、侵袭和招募具有直接刺激作用。这些效应被证明是通过 avb3 的 tetrac 抑制作用通过非基因组机制介导的。这一观察结果的可能分子机制之一是 T4/T3 介导的 MSC 缺氧反应网络的刺激，这在我们过去的资助期间也得到了证明。作为我们过去研究的逻辑结果，在下一个资助期内，我们将更详细地分析 T4、T3 和 tetrac 对 MSC 迁移的非基因组 avb3 介导作用的机制基础以及 MSC 介导的血管生成作用特别强调所涉及的信号通路的表征。为此，我们将分析 T4、T3 和 tetrac 对 1) 与 MSC 迁移相关的 MSC 细胞表面标志物、整合素和受体表达的影响，2) MSC 分泌的血管生成因子及其对内皮细胞的影响管形成。根据其他人和我们自己小组的初步数据，PI3K/Akt、MAPK 和规范 Wnt 通路是进一步分析其参与 MSC 生物学中 avb3 介导的 T4、T3 和 tetrac 非基因组效应的逻辑候选通路。因此，在当前的提议中，将通过分析在存在或不存在tetrac的情况下用T4、T3处理MSC后的下游靶标来研究这些途径，以及应用这些途径的特异性抑制剂后对MSC迁移和侵袭的影响。此外，将通过使用 NIS 作为报告基因的体外和体内通路响应报告测定来评估经典 Wnt 通路以及两个中央血管生成相关通路（Tie-2 和 VEGF 信号通路）的激活状态利用我们在 NIS 作为治疗诊断基因应用方面的长期专业知识。基于伤口愈合过程和肿瘤基质形成之间的强烈相似性，我们之前的研究中建立的肝癌异种移植小鼠模型将用作慢性伤口/组织修复的稳健模型。这些研究将显着增强我们对甲状腺激素 T4 和 T3 以及 tetrac 在慢性伤口/组织修复背景下 MSC 生物学调节中关键作用的理解。与此同时，我们的研究将扩大我们对整合素 avb3 作为甲状腺激素作用介质的不断演变的作用及其治疗意义的理解。