Lycopene attenuates trimethylamine-N-oxide-induced senescence in endothelial progenitor cells via the AMPK/SIRT1 pathway

Aging-related diseases, which are associated with the senescence of endothelial progenitor cells (EPCs), are consistently accompanied by elevated levels of circulating trimethylamine-N-oxide (TMAO), a marker predictive of poor prognosis. Lycopene (Lyc) deficiency has been demonstrated to be linked to these age-related diseases. The AMPK/SIRT1 pathway plays a pivotal role in cellular senescence. In this study, we hypothesize that lycopene could mitigate TMAO-induced EPCs senescence, with involvement of the AMPK/SIRT1 pathway. EPCs were subjected to treatment with TMAO, Lyc, small interfering RNA targeting AMP-activated protein kinase (siAMPK), or sirtin-1 (siSIRT1). The biological functions of EPCs were evaluated through, CCK-8, transwell and tube formation assays, while their senescence was assessed via SA-β-gal activity assay and Western blotting. ROS generation was measured using dichlorodihydrofluorescein diacetate staining. TMAO-induced suppression of EPCs’ functionality was alleviated by Lyc, but this effect was reversed by siAMPK and siSIRT1. TMAO increased SA-β-gal-positive cell number and ROS production, while reducing the expression of AMPK and SIRT1. These effects were attenuated by Lyc. However, the protective effects were diminished by siAMPK and siSIRT1. In conclusion, Lyc ameliorates TMAO-induced EPCs senescence through the AMPK/SIRT1 pathway.与内皮祖细胞（endothelial progenitor cells, EPCs）衰老相关的衰老相关疾病，通常伴随循环中三甲胺-N-氧化物（trimethylamine-N-oxide, TMAO）水平升高——该物质是预后不良的预测标志物。已有研究证实，番茄红素（lycopene, Lyc）缺乏与这类衰老相关性疾病存在密切关联。AMPK/SIRT1通路在细胞衰老进程中发挥关键调控作用。本研究提出假说：番茄红素可缓解TMAO诱导的内皮祖细胞衰老，且该保护效应依赖AMPK/SIRT1通路。 实验中，研究人员将内皮祖细胞分别用TMAO、Lyc、靶向AMP活化蛋白激酶的小干扰RNA（siAMPK）或靶向沉默信息调节因子1的小干扰RNA（siSIRT1）进行处理。通过CCK-8法、Transwell实验及管形成实验评估内皮祖细胞的生物学功能，通过衰老相关β-半乳糖苷酶（SA-β-gal）活性实验与蛋白质印迹法（Western blotting）检测细胞衰老水平；采用二氯二氢荧光素二乙酸酯染色法检测活性氧（reactive oxygen species, ROS）的生成量。 实验结果显示：TMAO对内皮祖细胞功能的抑制作用可被Lyc改善，但该保护效应可被siAMPK与siSIRT1逆转。TMAO可增加SA-β-gal阳性细胞数量与活性氧生成量，同时降低AMPK与SIRT1的蛋白表达水平；上述效应均可被Lyc削弱。而siAMPK与siSIRT1则会进一步抵消番茄红素的保护作用。 综上，番茄红素可通过AMPK/SIRT1通路改善TMAO诱导的内皮祖细胞衰老。