Rosarda Jessica D, Baron Kelsey R, Nutsch Kayla, Kline Gabriel M, Stanton Caroline, Kelly Jeffery W, Bollong Michael J, Wiseman R Luke
Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, United States.
Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States.
ACS Chem Biol. 2021 Dec 17;16(12):2852-2863. doi: 10.1021/acschembio.1c00810. Epub 2021 Nov 19.
The extracellular accumulation of glutamate is a pathologic hallmark of numerous neurodegenerative diseases including ischemic stroke and Alzheimer's disease. At high extracellular concentrations, glutamate causes neuronal damage by promoting oxidative stress, which can lead to cellular death. This has led to significant interest in developing pharmacologic approaches to mitigate the oxidative toxicity caused by high levels of glutamate. Here, we show that the small molecule proteostasis regulator AA147 protects against glutamate-induced cell death in a neuronal-derived cell culture model. While originally developed as an activator of the activating transcription factor 6 (ATF6) arm of the unfolded protein response, this AA147-dependent protection against glutamate toxicity is primarily mediated through activation of the NRF2-regulated oxidative stress response. We demonstrate that AA147 activates NRF2 selectively in neuronal-derived cells through a mechanism involving metabolic activation to a reactive electrophile and covalent modification of KEAP1─a mechanism analogous to that involved in the AA147-dependent activation of ATF6. These results define the potential for AA147 to protect against glutamate-induced oxidative toxicity and highlight the potential for metabolically activated proteostasis regulators like AA147 to activate both protective ATF6 and NRF2 stress-responsive signaling pathways to mitigate oxidative damage associated with diverse neurologic diseases.
谷氨酸在细胞外的积累是包括缺血性中风和阿尔茨海默病在内的多种神经退行性疾病的病理标志。在高细胞外浓度下，谷氨酸通过促进氧化应激导致神经元损伤，进而可导致细胞死亡。这引发了人们对开发药理学方法以减轻高浓度谷氨酸引起的氧化毒性的浓厚兴趣。在此，我们表明小分子蛋白质稳态调节剂AA147在神经元衍生的细胞培养模型中可保护细胞免受谷氨酸诱导的死亡。虽然AA147最初是作为未折叠蛋白反应的激活转录因子6（ATF6）臂的激活剂而开发的，但这种对谷氨酸毒性的AA147依赖性保护主要是通过激活NRF2调节的氧化应激反应来介导的。我们证明，AA147通过一种涉及代谢激活为反应性亲电试剂并对KEAP1进行共价修饰的机制，在神经元衍生的细胞中选择性激活NRF2 ── 这一机制类似于AA147依赖性激活ATF6所涉及的机制。这些结果确定了AA147预防谷氨酸诱导的氧化毒性的潜力，并突出了像AA147这样的代谢激活的蛋白质稳态调节剂激活保护性ATF6和NRF2应激反应信号通路以减轻与多种神经疾病相关的氧化损伤的潜力。
