Department of Advanced Medicine for Uremia, Nagoya University School of Medicine, Tsurumai-cho, Showa-ku, Nagoya, Japan.
J Ren Nutr. 2012 Jan;22(1):86-9. doi: 10.1053/j.jrn.2011.10.027.
BACKGROUND/AIM: We have reported that indoxyl sulfate (IS), a uremic toxin, accelerates proximal tubular cell senescence. Asymmetric dimethylarginine (ADMA), an inhibitor of nitric oxide synthase, has been reported to induce endothelial cell senescence. This study aimed to determine whether IS induces endothelial cell senescence in comparison with ADMA, and to investigate its molecular mechanism.
Human umbilical vein endothelial cells (HUVECs) were incubated with IS (250 μM) and/or ADMA (10 μM). These concentrations were comparable with their mean serum levels in hemodialysis patients. Cell senescence was evaluated by measuring senescence-associated beta-galactosidase (SA-β-gal) activity. N-acetylcysteine, an antioxidant, and pifithrin alpha p-nitro, a p53 inhibitor, were used to determine the role of reactive oxygen species (ROS) and p53 in the induction of cell senescence.
Both IS and ADMA significantly increased SA-β-gal activity in HUVECs. Further, some additional increase in SA-β-gal activity was observed when IS and ADMA were co-incubated. Preincubation of N-acetylcysteine or pifithrin alpha p-nitro significantly inhibited SA-β-gal activity induced by IS and ADMA in HUVECs. Thus, both IS and ADMA induced endothelial senescence through ROS and p53.
IS induces endothelial cell senescence by increasing ROS production and p53 activity, like ADMA.
背景/目的：我们曾报道过，尿毒症毒素硫酸吲哚酚（IS）可加速近端肾小管细胞衰老。作为一氧化氮合酶抑制剂的不对称二甲基精氨酸（ADMA）已被报道可诱导内皮细胞衰老。本研究旨在比较 IS 和 ADMA 诱导内皮细胞衰老的作用，并探讨其分子机制。
将人脐静脉内皮细胞（HUVEC）分别与 IS（250 μM）和/或 ADMA（10 μM）孵育。这两个浓度与血液透析患者的平均血清水平相当。通过测量衰老相关β-半乳糖苷酶（SA-β-gal）活性来评估细胞衰老。抗氧化剂 N-乙酰半胱氨酸和 p53 抑制剂 pifithrin alpha p-nitro 用于确定 ROS 和 p53 在诱导细胞衰老中的作用。
IS 和 ADMA 均可显著增加 HUVEC 中的 SA-β-gal 活性。此外，当 IS 和 ADMA 共同孵育时，SA-β-gal 活性进一步增加。N-乙酰半胱氨酸或 pifithrin alpha p-nitro 的预孵育可显著抑制 IS 和 ADMA 诱导的 HUVEC 中 SA-β-gal 活性。因此，IS 和 ADMA 均可通过 ROS 和 p53 诱导内皮细胞衰老。
IS 通过增加 ROS 生成和 p53 活性诱导内皮细胞衰老，与 ADMA 相似。
