Catalpol inhibits apoptosis in hydrogen peroxide-induced endothelium by activating the PI3K/Akt signaling pathway and modulating expression of Bcl-2 and Bax
Catalpol inhibits apoptosis in hydrogen peroxide-induced endothelium by activating the PI3K/Akt signaling pathway and modulating expression of Bcl-2 and Bax
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DOI：
10.1016/j.ejphar.2009.11.046
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发表时间：
2010-02-25
影响因子：
5
通讯作者：
Hu, Jian
中科院分区：
文献类型：
--
作者：
Hu, Lingai;Sun, Yukun;Hu, Jian
梓醇是一种存在于紫菀根中的环烯醚萜苷，已被证明可减少神经元细胞系的凋亡。最近的数据表明，梓醇也对其他细胞类型发挥抗凋亡作用。本研究的目的是探讨梓醇是否对过氧化氢（H2 O2）诱导的人脐静脉内皮细胞（HUVECs）凋亡的保护作用。通过末端脱氧核苷酸转移酶介导的脱氧尿苷三磷酸-生物素缺口末端标记、Annexin V-异硫氰酸荧光素结合试验和caspase-3活性评估来检测凋亡细胞。细胞内活性氧水平通过2 '，7'-二氯荧光素二乙酸酯测定来定量。采用实时半定量逆转录-聚合酶链反应（RT-PCR）和Western blotting检测Akt、Bad、Bcl-2和Bax mRNA和蛋白的表达。HUVECs凋亡与H2 O2暴露24 h后Bax增加、Bcl-2活性降低和Akt和Bad磷酸化失活有关。用梓醇预处理HUVECs显著降低H2 O2诱导的细胞内活性氧释放。梓醇不仅增加Bcl-2的表达，同时降低Bax的表达，而且诱导Akt活化和Bad磷酸化，最终减少H2 O2诱导的细胞凋亡。梓醇的保护作用可被磷脂酰肌醇3-激酶（PI 3 K）拮抗剂wortmannin或2-（4-morpholinyl）-8-phenyl-4 H-1-benzopyran-4-one（LY 294002）部分抑制。加在一起。这些结果表明，梓醇预处理HUVECs可阻断H2 O2诱导的细胞凋亡，其潜在机制涉及清除活性氧、激活PI 3 K/Akt-Bad信号通路、增加Bcl-2和降低Bax表达。(C)2009 Elsevier B. V.保留所有权利。
Catalpol, an iridoid glucoside found in the root of Rehmannia glutinosa Libosch, has been demonstrated to reduce apoptosis in neuronal cell lines. Recent data suggests that catalpol also exerts anti-apoptotic effects on other cell types. The aim of the present study was to investigate whether catalpol protects against hydrogen peroxide (H2O2) induced apoptosis in human umbilical vein endothelial cells (HUVECs). Apoptotic cells were detected by terminal deoxyribonucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling, Annexin V-fluorescein isothiocyanate binding assay and by assessment of caspase-3 activity. The level of intracellular reactive oxygen species was quantified by 2', 7'-dichlorofluorescein diacetate assay. Expression of Akt, Bad, Bcl-2 and Bax mRNA and protein was determined by real-time semiquantitative reverse transcription-polymerase chain reaction and Western blotting. Apoptosis in HUVECs was associated with increased Bax, decreased Bcl-2 activity and inactivated phosphorylation of Akt and Bad after 24 h of H2O2 exposure. Pre-treatment of HUVECs with catalpol significantly reduced H2O2-induced intracellular reactive oxygen species release. Catalpol not only increased the expression of Bcl-2, while decreasing Bax expression, but also induced Akt activation and Bad phosphorylation, and ultimately reduced H2O2-induced apoptosis. The protective effects of catalpol were partially inhibited by the phosphatidylinositol 3-kinase (PI3K) antagonist wortmannin or 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002). Taken together. these results suggest that pre-treatment of HUVECs with catalpol can block H(2)O2-induced apoptosis, and that the underlying mechanism involves reactive oxygen species scavenging, activation of the PI3K/Akt-Bad signaling pathway and increased Bcl-2 and decreased Bax expression. (C) 2009 Elsevier B.V. All rights reserved.