Department of Cardiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China.
J Cardiovasc Pharmacol. 2012 Mar;59(3):222-30. doi: 10.1097/FJC.0b013e31823c1d34.
Senescence of endothelial cells has been implicated in endothelial dysfunction and atherogenesis. This study investigated the effects of Rb1, a major ginsenoside in ginseng, on H2O2-induced senescence in primary human umbilical vein endothelial cells (HUVECs).
Real-time PCR and Western blot were used to detect the mRNA and protein expression, respectively. H2O2 (40∼100 μmol/L) effectively increased SA-β-gal activity and PAI-1 mRNA levels, two important senescence related biomarkers, in HUVECs, which were dramatically inhibited by Rb1 pre-incubation. Furthermore, Rb1 administration reversed the H2O2-decreased protein and mRNA levels of eNOS and its phosphorylation at Ser-1177, and the increased eNOS phosphorylation at Thr-495. As a result, Rb1 pretreatment restored the NO generation, as assayed by nitrate reductase method. However, pretreatment with L-NAME, a NOS inhibitor, abolished all the inhibitory effects of Rb1 on senescence. Importantly, Rb1 modulated the H2O2-altered caveolin-1 and pAkt, two most important regulators of eNOS expression and activity, in HUVECs.
We showed that Rb1 effectively protects HUVECs from senescence through eNOS modulation.
内皮细胞衰老与内皮功能障碍和动脉粥样硬化形成有关。本研究探讨了人参中主要的人参皂苷 Rb1 对过氧化氢诱导的原代人脐静脉内皮细胞（HUVEC）衰老的影响。
实时 PCR 和 Western blot 分别用于检测 mRNA 和蛋白表达。H2O2（40∼100 μmol/L）可有效增加 HUVEC 中 SA-β-半乳糖苷酶活性和 PAI-1 mRNA 水平，这是两种重要的衰老相关生物标志物，而 Rb1 预孵育可显著抑制其表达。此外，Rb1 给药可逆转 H2O2 降低的 eNOS 及其丝氨酸 1177 磷酸化的蛋白和 mRNA 水平，以及 eNOS 苏氨酸 495 磷酸化的增加。结果，用硝酸盐还原酶法测定，Rb1 预处理可恢复 NO 的生成。然而，NOS 抑制剂 L-NAME 的预处理消除了 Rb1 对衰老的所有抑制作用。重要的是，Rb1 调节了 H2O2 改变的 caveolin-1 和 pAkt，这是 eNOS 表达和活性的两个最重要的调节因子，在 HUVECs 中。
我们表明，Rb1 通过调节 eNOS 有效保护 HUVEC 免受衰老。
