Peng Yunqian, Kim Ji-Min, Park Hal-Sol, Yang Annie, Islam Celia, Lakatta Edward G, Lin Li
Laboratory of Cardiovascular Sciences, National Institute on Aging, National Institute of Health, Baltimore, MD 21224.
Sci Rep. 2016 Jan 5;6:18822. doi: 10.1038/srep18822.
Advanced glycation end products (AGEs) are sugar-modified biomolecules that accumulate in the body with advancing age, and are implicated in the development of multiple age-associated structural and functional abnormities and diseases. It has been well documented that AGEs signal via their receptor RAGE to activate several cellular programs including NF-κB, leading to inflammation. A large number of stimuli can activate NF-κB; yet different stimuli, or the same stimulus for NF-κB in different cellular settings, produce a very different transcriptional landscape and physiological outcome. The NF-κB barcode hypothesis posits that cellular network dynamics generate signal-specific post-translational modifications, or a "barcode" to NF-κB, and that a signature "barcode" mediates a specific gene expression pattern. In the current study, we established that AGE-RAGE signaling results in NF-κB activation that directs collagen Ia1 and Ia2 expression. We further demonstrated that AGE-RAGE signal induces phosphorylation of RelA at three specific residues, T254, S311, and S536. These modifications are required for transcription of collagen I genes and are a consequence of cellular network dynamics. The increase of collagen content is a hallmark of arterial aging, and our work provides a potential mechanistic link between RAGE signaling, NF-κB activation, and aging-associated arterial alterations in structure and function.
晚期糖基化终末产物(AGEs)是随着年龄增长在体内积累的糖修饰生物分子,与多种年龄相关的结构和功能异常及疾病的发生有关。已有充分文献证明,AGEs通过其受体RAGE发出信号,激活包括NF-κB在内的多个细胞程序,从而导致炎症。大量刺激可激活NF-κB;然而,不同的刺激,或在不同细胞环境中对NF-κB的相同刺激,会产生非常不同的转录图谱和生理结果。NF-κB条形码假说认为,细胞网络动态会产生信号特异性的翻译后修饰,即给NF-κB的一个“条形码”,并且一个特征性“条形码”介导特定的基因表达模式。在本研究中,我们确定AGE-RAGE信号传导导致NF-κB激活,进而指导胶原蛋白Ia1和Ia2的表达。我们进一步证明,AGE-RAGE信号在三个特定残基T254、S311和S536处诱导RelA磷酸化。这些修饰是胶原蛋白I基因转录所必需的,并且是细胞网络动态的结果。胶原蛋白含量的增加是动脉衰老的一个标志,我们的工作为RAGE信号传导、NF-κB激活以及衰老相关的动脉结构和功能改变之间提供了一个潜在的机制联系。