Liu Yu-Sheng, Xu Dong-Ling, Huang Zhi-Wei, Hao Lin, Wang Xin, Lu Qing-Hua
Department of Cardiology, the Second Hospital of Shandong University , Shandong , PR China.
Postgrad Med. 2015 Jun;127(5):446-54. doi: 10.1080/00325481.2015.1039451. Epub 2015 Apr 30.
Krüppel-like factor 2 (KLF2) is a transcription factor that regulates endothelial function and atorvastatin can stabilize atherosclerotic plaque and inhibit inflammation on endothelial cells by attenuating the role of cytokines. The aim of this study is to investigate the effect of high glucose (HG) on KLF2 expression in human umbilical vein endothelial cells (HUVECs) and the underlying mechanisms.
HUVECs were isolated from the human umbilical cords from normal pregnancies and exposed to medium containing 25.5 mM D-glucose for 24 hours as the HG induction model (HG group). In the HG plus atorvastatin groups or KLF2 gene transduction, the medium then was collected for the nitric oxide (NO) assay and the cells were harvested for Western blot and for the real-time polymerase chain reaction to observe the expression of KLF2, vascular cell adhesion molecule (VCAM)-1, intercellular adhesion molecule (ICAM)-1, total and phosphorylated endothelial NO synthase (eNOS), p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK)1/2, caspase-3 and cleaved caspase-3 and the role of the p38MAPK and ERK1/2 intracellular signal pathway. The cells' apoptosis was analyzed by flow cytometry.
HG dose-dependently increased apoptosis. The presence of HG inhibited the expression of KLF2 mRNA and protein in HUVECs and atorvastatin treatment increased KLF2 expression, thus counteracted HG-induced suppression of KLF2 expression, and overexpression of KLF2 might protect the cells from apoptosis. HG increased the expression of VCAM-1, ICAM-1, but decreased the nitric oxide release and the expression of p-eNOs/eNos in HUVECs. However, atorvastatin reversed these changes and also attenuated high-glucose induced p38 MAPK and ERK1/2 phosphorylation.
HG suppressed the KLF2 expression in HUVECs. The suppression was counteracted by atorvastatin treatment, probably via attenuating the activation of the signal pathyway p38 MAPK and ERK1/2.
Krüppel样因子2（KLF2）是一种调节内皮功能的转录因子，阿托伐他汀可通过减弱细胞因子的作用来稳定动脉粥样硬化斑块并抑制内皮细胞炎症。本研究旨在探讨高糖（HG）对人脐静脉内皮细胞（HUVECs）中KLF2表达的影响及其潜在机制。
从正常妊娠的人脐带中分离出HUVECs，并将其暴露于含有25.5 mM D-葡萄糖的培养基中24小时，作为HG诱导模型（HG组）。在HG加阿托伐他汀组或KLF2基因转导中，随后收集培养基进行一氧化氮（NO）测定，并收获细胞进行蛋白质印迹分析和实时聚合酶链反应，以观察KLF2、血管细胞粘附分子（VCAM）-1、细胞间粘附分子（ICAM）-1、总内皮型一氧化氮合酶（eNOS）和磷酸化内皮型一氧化氮合酶、p38丝裂原活化蛋白激酶（MAPK）、细胞外信号调节激酶（ERK）1/2、半胱天冬酶-3和裂解的半胱天冬酶-3的表达以及p38MAPK和ERK1/2细胞内信号通路的作用。通过流式细胞术分析细胞凋亡。
HG呈剂量依赖性增加细胞凋亡。HG的存在抑制了HUVECs中KLF2 mRNA和蛋白的表达，阿托伐他汀治疗增加了KLF2的表达，从而抵消了HG诱导的KLF2表达抑制，并且KLF2的过表达可能保护细胞免于凋亡。HG增加了VCAM-1、ICAM-1的表达，但降低了HUVECs中一氧化氮的释放以及p-eNOs/eNos的表达。然而，阿托伐他汀逆转了这些变化，并且还减弱了高糖诱导的p38 MAPK和ERK1/2磷酸化。
HG抑制了HUVECs中KLF2的表达。阿托伐他汀治疗可抵消这种抑制作用，可能是通过减弱信号通路p38 MAPK和ERK1/2的激活来实现的。
