Glutathionylated DNA adducts accumulate in mitochondrial DNA and are regulated by AP endonuclease 1 and tyrosyl-DNA phosphodiesterase 1

作者：Yu Hsuan Chen, María Esperanza Valdés Sánchez, Ta I Hung, Jin Tang, Wenyan Xu, Jiekai Yin, Yinsheng Wang, Chia‐en A. Chang, Huimin Zhang, Junjie Chen, Linlin Zhao · 发表于：Proceedings of the National Academy of Sciences · 年份：2025 · DOI：10.1073/pnas.2509312122 · 被引用次数：2 · 研究领域：Mitochondrial Function and Pathology、DNA Repair Mechanisms、DNA and Nucleic Acid Chemistry

Mitochondrial DNA (mtDNA) is crucial for cellular energy production, metabolism, and signaling. Its dysfunction is implicated in various diseases, including mitochondrial disorders, neurodegeneration, and diabetes. mtDNA is susceptible to damage by endogenous and environmental factors; however, unlike nuclear DNA (nDNA), mtDNA lesions do not necessarily lead to an increased mutation load in mtDNA. Instead, mtDNA lesions have been implicated in innate immunity and inflammation. Here, we report a type of mtDNA damage: glutathionylated DNA (GSH-DNA) adducts. These adducts are formed from abasic (AP) sites, key intermediates in base excision repair, or from alkylation DNA damage. Using mass spectrometry, we quantified the GSH-DNA lesion in both nDNA and mtDNA and found its significant accumulation in mtDNA of two different human cell lines, with levels one or two orders of magnitude higher than in nDNA. The formation of GSH-DNA adducts is influenced by TFAM and polyamines, and their levels are regulated by repair enzymes AP endonuclease 1 (APE1) and tyrosyl-DNA phosphodiesterase 1 (TDP1). The accumulation of GSH-DNA adducts is associated with the downregulation of several ribosomal and complex I subunit proteins and the upregulation of proteins related to redox balance and mitochondrial dynamics. Molecular dynamics (MD) simulations revealed that the GSH-DNA lesion stabilizes the TFAM-DNA binding, suggesting shielding effects from mtDNA transactions. Collectively, this study provi...