Department of Ophthalmology, First Affiliated Hospital of Jinan University, Guangzhou, China.
Department of Ophthalmology, Korea University College of Medicine, Seoul, South Korea.
Invest Ophthalmol Vis Sci. 2022 Sep 1;63(10):19. doi: 10.1167/iovs.63.10.19.
Sirtuin1 (SIRT1) as a hot therapeutic target for oxidative stress-associated diseases that has been extensively studied. This study aimed to determine the changes in SIRT1 expression in particulate matter (PM)-induced corneal and conjunctival epithelial cell damage and explore potential drugs to reduce PM-associated ocular surface injury.
Immortalized human corneal epithelial cells (HCECs) and human conjunctival epithelial cells (HCjECs) were exposed to an ambient PM sample. Cytotoxicity was evaluated by water-soluble tetrazolium salt-8 assay. SIRT1 expression was measured by Western blot analysis. Reactive oxygen species (ROS) production, cell apoptosis, mitochondrial function, and cell senescence were assessed by using 2',7'-dichlorofluorescein diacetate assay, annexin V apoptosis assay, tetramethylrhodamine ethyl ester assay, and senescence β-galactosidase staining, respectively.
PM-induced cytotoxicity of HCECs and HCjECs occurred in a dose-dependent manner. Increased ROS production, as well as decreased SIRT1 expression, were observed in HCECs and HCjECs after 200 µg/mL PM exposure. In addition, PM induced oxidative stress-mediated cellular damage, including cell apoptosis, mitochondrial damage, and cell senescence. Interestingly, SRT1720, a SIRT1 activator, increased SIRT1 expression and decreased ROS production and attenuated PM-induced cell damage in HCECs and HCjECs.
This study determined that SIRT1 was involved in PM-induced oxidative stress in HCECs and HCjECs and found that ROS overproduction may a key factor in PM-induced SIRT1 downregulation. The SIRT1 activator, SRT1720, can effectively upregulate SIRT1 expression and inhibit ROS production, thereby reversing PM-induced cell damage. This study provides a new potential target for clinical treatment of PM-associated ocular surface diseases.
Sirtuin1（SIRT1）作为一种与氧化应激相关疾病的热门治疗靶点，已得到广泛研究。本研究旨在确定 SIRT1 表达在颗粒物（PM）诱导的角膜和结膜上皮细胞损伤中的变化，并探索潜在的药物来减少 PM 相关的眼表损伤。
将永生化人角膜上皮细胞（HCECs）和人结膜上皮细胞（HCjECs）暴露于环境 PM 样本中。通过水溶性四唑盐-8 测定法评估细胞毒性。通过 Western blot 分析测量 SIRT1 表达。通过 2'，7'-二氯荧光素二乙酸酯测定法、膜联蛋白 V 凋亡测定法、四甲基罗丹明乙酯测定法和衰老β-半乳糖苷酶染色法分别评估活性氧（ROS）产生、细胞凋亡、线粒体功能和细胞衰老。
PM 对 HCECs 和 HCjECs 的细胞毒性呈剂量依赖性。在 200μg/mL PM 暴露后，观察到 HCECs 和 HCjECs 中 ROS 产生增加和 SIRT1 表达降低。此外，PM 诱导氧化应激介导的细胞损伤，包括细胞凋亡、线粒体损伤和细胞衰老。有趣的是，SIRT1 激活剂 SRT1720 增加了 SIRT1 的表达，减少了 ROS 的产生，并减轻了 HCECs 和 HCjECs 中 PM 诱导的细胞损伤。
本研究确定 SIRT1 参与了 HCECs 和 HCjECs 中 PM 诱导的氧化应激，发现 ROS 过度产生可能是 PM 诱导 SIRT1 下调的关键因素。SIRT1 激活剂 SRT1720 可以有效上调 SIRT1 表达并抑制 ROS 产生，从而逆转 PM 诱导的细胞损伤。本研究为 PM 相关眼表疾病的临床治疗提供了一个新的潜在靶点。
