Up-Regulation of CREG Expression by the Transcription Factor GATA1 Inhibits High Glucose- and High Palmitate-Induced Apoptosis in Human Umbilical Vein Endothelial Cells.
Up-Regulation of CREG Expression by the Transcription Factor GATA1 Inhibits High Glucose- and High Palmitate-Induced Apoptosis in Human Umbilical Vein Endothelial Cells.
复制标题
转录因子 GATA1 上调 CREG 表达抑制高葡萄糖和高棕榈酸诱导的人脐静脉内皮细胞凋亡
DOI：
10.1371/journal.pone.0154861
复制
发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Han Y
中科院分区：
文献类型：
--
作者：
Liu Y;Tian X;Li Y;Liu D;Liu M;Zhang X;Zhang Q;Yan C;Han Y
背景血管内皮细胞凋亡在糖尿病患者动脉粥样硬化的发病机制中起重要作用，但其机制尚不清楚。E1a刺激基因的细胞抑制因子(CREG)是一个新的基因，被报道参与维持内皮细胞的动态平衡。因此，在本研究中，我们研究了CREG在高糖/高棕榈酸诱导的EC凋亡中的作用，并破译了CREG转录调控的上游调控机制。方法检测2型糖尿病(T2 DM)患者下肢动脉粥样硬化病变组织中CREG的表达及细胞凋亡率。原代培养的人脐静脉内皮细胞在高糖/高棕榈酸酯(25 mmol/L D-葡萄糖，0.4 mmol/L棕榈酸酯)中培养，通过CREG的过度表达和下调，以确定CREG在内皮细胞凋亡中的作用。通过启动子结合转录因子谱阵列、染色质免疫沉淀(ChIP)分析和突变分析鉴定了CREG的上游调控机制。结果与非糖尿病患者相比，T2 DM患者动脉粥样硬化病变血管内皮细胞CREG表达降低，细胞凋亡率增加。体外培养的HUVECs在高糖/高棕榈酸介质中处理后，CREG表达降低，细胞凋亡率增加。此外，高糖/高棕榈酸诱导的HUVEC凋亡可通过CREG的下调而增加，并可通过CREG的过度表达而被挽救。我们还证明了GATA1能够与人CREG基因的启动子结合。CREG启动子-297/-292处的缺失突变破坏了GATA1结合，使CREG转录活性降低约83.3%。GATA1的过表达可抑制高糖/高棕榈酸诱导的HUVECs的凋亡。结论CREG过表达可抑制高糖/高棕榈酸诱导的HUVEC凋亡。CREG在转录上被GATA1上调。因此，CREG可能成为干预糖尿病相关血管并发症的潜在治疗靶点。
Background Endothelial cell (EC) apoptosis plays a vital role in the pathogenesis of atherosclerosis in patients with diabetes mellitus (DM), but the underlying mechanism remains unclear. Cellular repressor of E1A-stimulated genes (CREG) is a novel gene reported to be involved in maintaining the homeostasis of ECs. Therefore, in the present study, we investigated the role of CREG in high glucose/high palmitate-induced EC apoptosis and to decipher the upstream regulatory mechanism underlying the transcriptional regulation of CREG. Methods The expression of CREG and the rate of apoptosis were assessed in lower-limb atherosclerotic lesions from patients with type 2 DM (T2DM). Primary human umbilical vein endothelial cells (HUVECs) were isolated and cultured in a high glucose/high palmitate medium (25 mmol/L D-glucose, 0.4 mmol/L palmitate), and the over-expression and knock-down of CREG were performed in HUVECs to determine the role of CREG in EC apoptosis. The upstream regulatory mechanism of CREG was identified using a promoter-binding transcription-factor profiling array, chromatin immunoprecipitation (ChIP) assay and a mutation analysis. Results Compared with normal arteries from non-diabetic patients, reduced CREG expression and increased apoptosis were found in the endothelium of atherosclerotic lesions from patients with T2DM. In vitro treatment of HUVECs with a high glucose/high palmitate medium also resulted in decreased CREG expression and increased apoptosis. Moreover, high glucose/high palmitate induced-HUVEC apoptosis was increased by the knock-down of CREG and rescued by the over-expression of CREG. We also demonstrated that GATA1 was able to bind to the promoter of the human CREG gene. A deletion mutation at -297/-292 in the CREG promoter disrupted GATA1 binding and reduced the activation of CREG transcription by approximately 83.3%. Finally, the overexpression of GATA1 abrogated the high glucose/high palmitate-induced apoptosis in HUVECs. Conclusions The over-expression of CREG inhibits high glucose/high palmitate-induced apoptosis in HUVECs. CREG is transcriptionally upregulated by GATA1. Thus, CREG might be a potential therapeutic target for intervention of vascular complications related to diabetes.