Abstract

Oxidative stress is recognised as a key factor that can lead to cellular senescence and aging. Carbon monoxide (CO) is produced by haemoxygenase-1 (HO-1), which exerts cytoprotective effects in aging-related diseases, whereas the effect of CO on cellular senescence and aging has not been elucidated. In the current study, we clearly demonstrated that CO delays the process of cellular senescence and aging through regulation of miR-34a and Sirt1 expression. CO reduced H₂O₂-induced premature senescence in human diploid fibroblast WI-38 cells measured with SA-β-Gal-staining. Furthermore, CO significantly decreased the expression of senescence-associated secretory phenotype (SASP), including TNF-α IL-6, and PAI-1 and increased the transcriptional levels of antioxidant genes, such as HO-1 and NQO1. Moreover, CO apparently enhanced the expression of Sirt1 through down-regulation of miR-34a. Next, to determine whether Sirt1 mediates the inhibitory effect of CO on cellular senescence, we pre-treated WI-38 cells with the Sirt1 inhibitor Ex527 and a miR-34a mimic followed by the administration of H₂O₂ and evaluated the expression of SASP and antioxidant genes as well as ROS production. According to our results, Sirt1 is crucial for the antiaging and antioxidant effects of CO. Finally, CO prolonged the lifespan of Caenorhabditis elegans and delayed high-fat diet-induced liver aging. Taken together, these findings demonstrate that CO reduces cellular senescence and liver aging through the regulation of miR-34a and Sirt1.

摘要

氧化应激被认为是导致细胞衰老和衰老的关键因素。一氧化碳 (CO) 由血氧合酶-1 (HO-1) 产生，其在衰老相关疾病中发挥细胞保护作用，而 CO 对细胞衰老和衰老的影响尚未阐明。在目前的研究中，我们清楚地证明了 CO 通过调节 miR-34a 和 Sirt1 的表达来延缓细胞衰老和衰老的过程。CO 还原 H ₂ O ₂用 SA-β-Gal 染色测量的人二倍体成纤维细胞 WI-38 细胞中诱导的过早衰老。此外，CO 显着降低衰老相关分泌表型 (SASP) 的表达，包括 TNF-α IL-6 和 PAI-1，并增加抗氧化基因的转录水平，如 HO-1 和 NQO1。此外，CO 显然通过下调 miR-34a 增强了 Sirt1 的表达。接下来，为了确定 Sirt1 是否介导 CO 对细胞衰老的抑制作用，我们用 Sirt1 抑制剂 Ex527 和 miR-34a 模拟物预处理 WI-38 细胞，然后施用 H ₂ O ₂并评估了 SASP 和抗氧化基因的表达以及 ROS 的产生。根据我们的研究结果，Sirt1 对 CO 的抗衰老和抗氧化作用至关重要。最后，CO 延长了秀丽隐杆线虫的寿命并延迟了高脂肪饮食引起的肝脏衰老。总之，这些发现表明 CO 通过调节 miR-34a 和 Sirt1 来减少细胞衰老和肝脏衰老。