Patients with chronic kidney disease (CKD) often exhibit increased level of oxidative stress that contribute to the deterioration of renal function and uremic complications. White adipose tissue (WAT) has been recognized as a major site of production of radical oxygen species (ROS) in the context of metabolic diseases. This study was designed to decipher whether the protein bound uremic toxin p-cresyl-sulfate (p-CS) could contribute to ROS production in WAT and promote oxidative stress. Mouse 3T3-L1 adipocytes were incubated for 2 hours in culture medium containing 212 μM p-CS, a concentration chosen to mimic levels encountered in end stage renal disease patients or KCl as a control and intracellular ROS production was measured using the fluorescent probe 5-6-carboxy-2′,7′-dichlorodihydrofluorescein diacetate. Oxidative insult was estimated by the measurement of malondialdehyde (MDA) content and glutathione content. The effects of probenecid (1mM) a potent inhibitor of organic anion transporter, apocynin (1mM) an inhibitor of NADPH oxidase or common antioxidants such as α-tocopherol (2.5 μM), ascorbate (200μM), and N-acetylcysteine (500 μM) were further evaluated. p-CS triggered a striking increase in ROS production (+228%, p < 0.01), in MDA content (+214%, p < 0.005) and a decrease in glutathione (−47%, P < 0.01). Pre-treatment of cells with probenecid, apocynin or antioxidants prevented the p-CS induced ROS production and oxidative insults. These results suggest that in uremic state, the intracellular accumulation of p-CS in adipose cells could contribute, through an activation of NADPH oxidase, to the redox imbalance often reported in CKD patients.

慢性肾病 (CKD) 患者通常表现出氧化应激水平升高，这会导致肾功能恶化和尿毒症并发症。在代谢疾病的背景下，白色脂肪组织 (WAT) 已被认为是产生自由基氧 (ROS) 的主要部位。本研究旨在破译蛋白质结合的尿毒症毒素对甲酚硫酸盐 (p-CS) 是否有助于 WAT 中的 ROS 产生并促进氧化应激。将小鼠 3T3-L1 脂肪细胞在含有 212 μM p-CS 的培养基中培养 2 小时，该浓度选择模拟终末期肾病患者或 KCl 作为对照中遇到的水平，并使用荧光探针测量细胞内 ROS 的产生 5- 6-羧基-2',7'-二氯二氢荧光素二乙酸酯。通过测量丙二醛 (MDA) 含量和谷胱甘肽含量来估计氧化损伤。丙磺舒 (1mM) 是一种有效的有机阴离子转运蛋白抑制剂，夹竹桃素 (1mM) 是一种 NADPH 氧化酶抑制剂或常见的抗氧化剂，如 α-生育酚 (2.5 μM)、抗坏血酸 (200μM) 和 N-乙酰半胱氨酸 (500 μM) 的作用被进一步评估。p-CS 引发了 ROS 产生（+228%，p < 0.01）、MDA 含量（+214%，p < 0.005）和谷胱甘肽减少（-47%，P < 0.01）的显着增加。用丙磺舒、夹竹桃素或抗氧化剂预处理细胞可防止 p-CS 诱导的 ROS 产生和氧化损伤。这些结果表明，在尿毒症状态下，脂肪细胞中 p-CS 的细胞内积累可能有助于通过激活 NADPH 氧化酶，