背景和目的：细胞衰老是一个复杂的生物学过程，涉及多种内外源性因素的共同作用。活性氧（ROS）作为细胞代谢的副产物，在细胞衰老过程中扮演了重要角色。ROS的过量生成会导致氧化应激，对细胞内的生物大分子（包括核酸、蛋白质及脂质）造成损伤，进而激活多种信号通路的级联反应，最终导致细胞衰老。研究表明，ROS不仅直接损伤细胞，还可以通过上调细胞的炎症反应，进一步加速衰老过程。然而，ROS如何通过调控炎症反应促进细胞衰老，其具体的分子机制尚未完全明了。本研究首次在外周血细胞中检测了氧化核苷酸和氧化microRNA的含量，探索衰老过程中核酸氧化修饰和炎症因子产生的机制。方法：研究基于中国PENG ZU队列，选取不同年龄段健康志愿者，通过液相色谱-串联质谱（LC-MS/MS）法检测外周血白细胞中核酸及核苷酸池的氧化水平。然后，我们通过细胞因子芯片检测了血浆中细胞因子随增龄的变化。此外，我们利用 miRNA氧化修饰测序（o⁸G-miSeq）分析白细胞中miRNA的氧化修饰谱；最后，我们通过ELISA、荧光素酶报告基因实验、RT-qPCR和Western blot等技术，在体外细胞模型中研究了氧化 miRNA 对靶基因的调控作用及其对炎症和衰老通路的影响。结果：我们的研究发现增龄过程中外周血白细胞中DNA和RNA的氧化水平显著升高，而且RNA更易受到氧化损伤。我们成功建立了白细胞的核苷酸池检测体系，通过UPLC-MS/MS检测发现白细胞的核苷酸池中8-oxoGTP含量随年龄增长显著增加。通过细胞因子芯片检测发现血浆中炎症因子ICAM1和CXCL16表达随增龄显著升高，与白细胞核苷酸池中8-oxoGTP水平呈正相关。通过o⁸G-miSeq，我们发现白细胞中许多miRNA种子区域发生了8-oxoG氧化修饰，并且氧化水平随增龄显著升高。其中，调控ICAM1的 miR-98-5p 和调控CXCL16的miR-8085等miRNA 的氧化修饰削弱了其对靶基因的抑制作用，导致ICAM1和CXCL16表达增加。此外，通过转录组测序以及Western blot实验，我们发现氧化的miRNA可以通过o⁸G : A碱基错配调控新的靶基因。氧化miRNA（如5o⁸G-miR-98-5p和2o⁸G-miR-8085）重新靶向抗炎基因CLEC10A、EBI3和IFNB1，抑制其表达，进一步加剧炎症反应。值得注意的是，氧化miRNA通过调控炎症因子和衰老相关蛋白（如P21），激活p38 MAPK和NF-κB炎症通路，形成炎症和氧化应激的正反馈机制。结论：本研究首次系统揭示了增龄过程中miRNA种子区域的氧化修饰在衰老相关炎症中的关键作用。氧化miRNA通过削弱对原有靶基因的抑制作用并重新靶向抗炎基因，重塑基因调控网络，激活炎症通路，加剧炎症反应和细胞衰老。这一发现为理解衰老相关疾病的分子机制提供了新视角，并为干预衰老相关炎症提供了潜在的治疗靶点

Background and Objectives: Cellular aging is a complex biological process influenced by a combination of intrinsic and extrinsic factors. Reactive oxygen species (ROS), as byproducts of cellular metabolism, play a critical role in the aging process. Excessive ROS production leads to oxidative stress, damaging cellular macromolecules such as nucleic acid, proteins, and lipids, ultimately triggering various signaling pathways that result in cellular senescence. Studies have shown that ROS directly damages cells and exacerbates the aging process by amplifying inflammatory responses. However, the precise molecular mechanisms by which ROS regulate inflammation to promote cellular aging remain unclear. This study is the first to investigate the content of oxidized nucleotides and oxidized microRNAs (miRNAs) in peripheral blood cells, aiming to elucidate the mechanisms by which nucleic acid oxidation and inflammatory factor production are interconnected during aging. Methods: This study was based on the Chinese PENG ZU cohort, selecting healthy volunteers from different age groups. Oxidative levels of nucleic acids and nucleotide pools in peripheral blood leukocytes were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Cytokine profiling was performed using cytokine arrays to observe age-related changes in plasma cytokines. Additionally, miRNA oxidation modification profiles in leukocytes were analyzed using o8G-miSeq. Finally, the regulatory effects of oxidized miRNAs on their target genes and their impact on inflammatory and aging pathways were studied in vitro using ELISA, luciferase reporter assays, RT-qPCR, and Western blot. Results: Our study revealed that oxidative levels of DNA and RNA in peripheral blood leukocytes significantly increased with age, with RNA being more susceptible to oxidative damage. A nucleotide pool detection system was successfully established, and UPLC-MS/MS analysis showed that the levels of 8-oxoGTP in leukocyte nucleotide pools increased significantly with age. Cytokine array analysis demonstrated that the expression of inflammatory factors ICAM1 and CXCL16 in plasma significantly increased with age and was positively correlated with 8-oxoGTP levels in leukocyte nucleotide pools. Using o8G-miSeq, we found that many miRNAs in leukocytes exhibited 8-oxoG modifications in their seed regions, with oxidation levels significantly rising with age. Notably, the oxidized modifications of miR-98-5p, which regulates ICAM1, and miR-8085, which regulates CXCL16, weakened their suppressive effects on these target genes, leading to increased ICAM1 and CXCL16 expression. Furthermore, transcriptome sequencing and Western blot analysis revealed that oxidized miRNAs could regulate new target genes through o8G:A base mismatches. Oxidized miRNAs, such as 5o8G-miR-98-5p and 2o8G-miR-8085, were found to retarget anti-inflammatory genes CLEC10A, EBI3, and IFNB1, suppressing their expression and further exacerbating inflammatory responses. Oxidized miRNAs activated the p38 MAPK and NF-κB inflammatory pathways by regulating inflammatory factors and aging-related proteins (e.g., P21), creating a positive feedback loop between inflammation and oxidative stress. Conclusion: This study systematically reveals, for the first time, the critical role of miRNA seed region oxidation in age-related inflammation. Oxidized miRNAs reshape gene regulatory networks by weakening their suppression of original target genes and retargeting anti-inflammatory genes, thereby activating inflammatory pathways and exacerbating both inflammation and cellular aging. These findings provide new insights into the molecular mechanisms underlying age-related diseases and offer potential therapeutic targets for mitigating aging-associated inflammation.