The NTHL1 and NEIL1-3 DNA glycosylases are major enzymes in the removal of oxidative DNA base lesions, via the base excision repair (BER) pathway. It is expected that lack of these DNA glycosylases activities would render cells vulnerable to oxidative stress, promoting cell death. Intriguingly, we found that single, double, triple, and quadruple DNA glycosylase knockout HAP1 cells are, however, more resistant to oxidative stress caused by genotoxic agents than wild type cells. Furthermore, glutathione depletion in NEIL deficient cells further enhances resistance to cell death induced via apoptosis and ferroptosis. Finally, we observed higher basal level of glutathione and differential expression of NRF2-regulated genes associated with glutathione homeostasis in the NEIL triple KO cells. We propose that lack of NEIL DNA glycosylases causes aberrant transcription and subsequent errors in protein synthesis. This leads to increased endoplasmic reticulum stress and proteotoxic stress. To counteract the elevated intracellular stress, an adaptive response mediated by increased glutathione basal levels, rises in these cells. This study reveals an unforeseen role of NEIL glycosylases in regulation of resistance to oxidative stress, suggesting that modulation of NEIL glycosylase activities is a potential approach to improve the efficacy of e.g. anti-inflammatory therapies.

NTHL1 和 NEIL1-3 DNA 糖基化酶是通过碱基切除修复 (BER) 途径去除氧化 DNA 碱基损伤的主要酶。预计缺乏这些 DNA 糖基化酶活性将使细胞容易受到氧化应激，从而促进细胞死亡。有趣的是，我们发现单、双、三和四 DNA 糖基化酶敲除的 HAP1 细胞比野生型细胞更能抵抗基因毒性剂引起的氧化应激。此外，NEIL 缺陷细胞中谷胱甘肽的消耗进一步增强了对细胞凋亡和铁死亡诱导的细胞死亡的抵抗力。最后，我们在 NEIL 三重 KO 细胞中观察到较高的谷胱甘肽基础水平以及与谷胱甘肽稳态相关的 NRF2 调节基因的差异表达。我们认为缺乏 NEIL DNA 糖基化酶会导致转录异常以及随后的蛋白质合成错误。这导致内质网应激和蛋白毒性应激增加。为了抵消升高的细胞内应激，这些细胞中增加了由谷胱甘肽基础水平升高介导的适应性反应。这项研究揭示了 NEIL 糖基化酶在调节氧化应激抵抗力方面的不可预见的作用，表明调节 NEIL 糖基化酶活性是提高例如的功效的潜在方法。抗炎治疗。