Choi Sung-E, Kang Yup, Jang Hyun-Ju, Shin Ha-Chul, Kim Hyo-Eun, Kim Hyo-Soo, Kim Hae Jin, Kim Dae Jung, Lee Kwan-Woo
Department of Endocrinology and Metabolism, Ajou University School of Medicine, Suwon, Republic of Korea.
J Vasc Res. 2007;44(5):365-74. doi: 10.1159/000102321. Epub 2007 May 4.
BACKGROUND/AIMS: The death of endothelial cells may play a critical role in the development of various vascular diseases, including atherosclerosis. While free fatty acids (FFAs) may stimulate endothelial apoptosis, the molecular and cellular mechanisms of this effect have not been studied intensively. To elucidate the mechanisms involved in FFA-induced endothelial cell apoptosis, we investigated the effect of different pharmacological inhibitors on palmitate-induced apoptosis in human umbilical vein endothelial cells (HUVECs). Interestingly, lithium, a glycogen synthase kinase-3 (GSK-3) inhibitor, showed a strong protective effect.
To examine the involvement of GSK-3beta in palmitate-induced HUVEC apoptosis, its dephosphorylation at Ser9 and enzymatic activation in response to palmitate treatment were monitored by immunoblotting and in vitro kinase assays, respectively. GSK-3beta was dephosphorylated and its enzymatic activity increased in palmitate-treated HUVECs. In addition, pretreatment with other GSK-3beta inhibitors, e.g. SB216763 or TDZD-8, as well as adenoviral transduction with a catalytically inactive GSK-3beta had significant protective effects against palmitate-induced HUVEC apoptosis.
These results demonstrate that the GSK-3beta signalling pathway is involved in palmitate-induced HUVEC apoptosis.
背景/目的：内皮细胞死亡可能在包括动脉粥样硬化在内的各种血管疾病的发展中起关键作用。虽然游离脂肪酸（FFA）可能刺激内皮细胞凋亡，但这种作用的分子和细胞机制尚未得到深入研究。为了阐明FFA诱导内皮细胞凋亡的机制，我们研究了不同药理抑制剂对棕榈酸诱导人脐静脉内皮细胞（HUVECs）凋亡的影响。有趣的是，糖原合酶激酶-3（GSK-3）抑制剂锂显示出强大的保护作用。
为了检测GSK-3β在棕榈酸诱导的HUVEC凋亡中的作用，分别通过免疫印迹和体外激酶测定监测其在Ser9位点的去磷酸化以及对棕榈酸处理的酶活性激活。在棕榈酸处理的HUVECs中，GSK-3β发生去磷酸化且其酶活性增加。此外，用其他GSK-3β抑制剂（如SB216763或TDZD-8）预处理，以及用催化失活的GSK-3β进行腺病毒转导，对棕榈酸诱导的HUVEC凋亡具有显著的保护作用。
这些结果表明GSK-3β信号通路参与了棕榈酸诱导的HUVEC凋亡。
