Cellular Repressor Of E1A-stimulated Genes Research Articles

MicroRNA miR-505-5p Promotes Oxygen-Glucose Deprivation/Reoxygenation-Induced Neuronal Injury via Negative Regulation of CREG1 in Cultured Neuron-Like Cells

Cerebral ischemia/reperfusion (I/R) injury is associated with various cardiovascular and cerebrovascular diseases with high disability, morbidity, and mortality rates. MicroRNAs (miRNAs) are related to the pathogenesis of the above diseases. MiR-505-5p, a kind of such miRNAs, was found to be highly expressed in cerebral I/R injuries, but the mechanism of action of this miRNA in cerebral I/R injury was unclear. In our study, up-regulation of miR-505-5p was detected in cultured oxygen-glucose deprivation/reoxygenation (OGD/R)-subjected PC12 and HEC293 cells. Silencing of miR-505-5p in OGD/R-affected neuron-like cells not only decreased the OGD/R-injury (according to cell viability, SOD increase, and LDH and MDA decreases), but also reduced apoptosis (decreasing the cleaved caspase-3 and PARP protein levels). Interestingly, expression of CREG1 (Cellular Repressor of E1Astimulated Genes 1) was low in OGD/R-subjected neurons; it was verified as a possible target gene of miR-505-5p. CREG1 knockdown can reverse the effect of miR-505-5p silencing in OGD/R-induced neural injury. Taken together, the data obtained provide a new target for cerebral I/R injury treatment.

Epoxyeicosatrienoic intervention improves NAFLD in leptin receptor deficient mice by an increase in HO-1-PGC1α mitochondrial signaling

BackgroundNon-alcoholic fatty liver disease (NAFLD) is associated with obesity and is considered to be an inflammatory disorder characterized by fatty acid accumulation, oxidative stress, and lipotoxicity. We have previously reported that epoxyeicosatrienoic acid-agonist (EET-A) has multiple beneficial effects on cardiac, renal and adipose tissue function while exhibiting both anti-inflammatory and anti-oxidant activities. We hypothesized that EET-A intervention would play a central role in attenuation of obesity-induced steatosis and hepatic fibrosis that leads to NAFLD. MethodsWe studied the effect of EET-A on fatty liver using db/db mice as a model of obesity. Mice were fed a high fat diet (HFD) for 16 weeks and administered EET-A twice weekly for the final 8 weeks. Resultsdb/db mice fed HFD significantly increased hepatic lipid accumulation as manifested by increases in NAS scores, hepatic fibrosis, insulin resistance, and inflammation, and decreases in mitochondrial mitofusin proteins (Mfn 1/2) and anti-obesity genes Fibroblast growth factor 21 (FGF21) and Cellular Repressor of E1A-Stimulated Genes 1 (CREG1). EET-A administration reversed the decrease in these genes and reduced liver fibrosis. Knockout of Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) in EET-A treated mice resulted in a reversal of the beneficial effects of EET-A administration. ConclusionsEET-A intervention diminishes fatty acid accumulation, fibrosis, and NFALD associated with an increase in HO-1-PGC1α and increased insulin receptor phosphorylation. A pharmacological strategy involving EETs may offer a potential therapeutic approach in preventing fibrosis, mitochondrial dysfunction, and the development of NAFLD.

Creg in Hepatocytes Ameliorates Liver Ischemia/Reperfusion Injury in a TAK1-Dependent Manner in Mice.

Hepatic ischemia/reperfusion (I/R) is a major challenge for liver surgery and specific severe conditions of chronic liver disease. Current surgical and pharmacological strategies are limited to improve liver function after hepatic I/R injury. Thus, an in-depth understanding of the liver I/R mechanism is pivotal to develop new therapeutic methods. The cellular repressor of E1A-stimulated genes (Creg), a key regulator of cellular proliferation, exerts protective roles in cardiovascular diseases and participates in lipid accumulation and inflammatory response in the liver. However, the role of Creg in hepatic I/R remains largely unknown. A genetic engineering technique was used to explore the function of Creg in hepatic I/R injury. Hepatocyte-specific Creg knockout (CregΔHep ) and transgenic mice were generated and subjected to hepatic I/R injury, as were the controls. Creg in hepatocytes prevented against liver I/R injury by suppressing cell death and inflammation. In vitro studies were performed using primary hepatocytes isolated from CregΔHep that were challenged by hypoxia/reoxygenation insult. These cells exhibited more cell death and inflammatory cytokines production similar to observations in vivo. Moreover, further molecular experiments showed that Creg suppressed mitogen-activated protein kinase (MAPK) signaling by inhibiting TAK1 (TGF-β-activated kinase 1) phosphorylation. Inhibiting TAK1 by 5Z-7-ox or mutating the TAK1-binding domain of Creg abolished the protective role of Creg indicating that Creg binding to TAK1 was required for prevention against hepatic I/R injury. Conclusion: These data demonstrate that Creg prevents hepatocytes from liver I/R injury. The Creg-TAK1 interaction inhibited the phosphorylation of TAK1 and the activation of MAPK signaling, which protected against cell death and inflammation during hepatic I/R injury.

The Structure and Biological Function of CREG.

The cellular repressor of E1A-stimulated genes (CREG) is a 220 amino acid glycoprotein structurally similar to oxidoreductases. However, CREG does not have enzymatic activities because it cannot bind to the cofactor flavin mononucleotide. Although CREG can be secreted, it is mainly an intracellular protein localized in the endocytic-lysosomal compartment. It undergoes proteolytic maturation mediated by lysosomal cysteine proteases. Biochemical studies have demonstrated that CREG interacts with mannose-6-phosphate/insulin-like growth factor-2 receptor (M6P/IGF2R) and exocyst Sec8. CREG inhibits proliferation and induces differentiation and senescence when overexpressed in cultured cells. In Drosophila, RNAi-mediated knockdown of CREG causes developmental lethality at the pupal stage. In mice, global deletion of the CREG1 gene leads to early embryonic death. These findings establish an essential role for CREG in development. CREG1 haploinsufficient and liver-specific knockout mice are susceptible to high fat diet-induced obesity, hepatic steatosis and insulin resistance. The purpose of this review is to provide an overview of what we know about the biochemistry and biology of CREG and to discuss the important questions that remain to be addressed in the future.

CREG1 promotes uncoupling protein 1 expression and brown adipogenesis in vitro.

Brown adipocytes play a critical role for adaptive thermogenesis to regulate body temperature in cold or to circumvent diet-induced obesity. In this study, we investigated the role of cellular repressor of E1A-stimulated genes 1 (CREG1) on brown adipogenesis and uncoupling protein 1 (UCP1) expression by using in vitro culture models. In murine mesenchymal stem cell line C3H10T1/2, Creg1 mRNA expression significantly increased in a time-dependent manner along with Ucp1 mRNA induction in brown adipogenesis. Creg1 gene overexpression upregulated the expression of brown fat-related genes including Ucp1 but its suppression downregulated these gene expression in C3H10T1/2 cells. Unlike the brown adipogenesis, Creg1 mRNA expression decreased significantly after differentiation stimulation in white adipogenesis of 3T3-L1 cells. Either Creg1 gene overexpression or suppression hardly affected white adipogenesis. In addition, CREG1 protein stimulated brown adipogenesis and rescued the adipogenesis in the absence of thyroid hormone in C3H10T1/2 cells. In reporter assay, CREG1 induction stimulated Ucp1 promoter activity, which was enhanced by co-expression with thyroid hormone receptors. The effect of CREG1 on Ucp1 promoter activity was also stimulated by retinoic acid. These results strongly suggest that CREG1 plays an important role on the regulation of UCP1 expression and brown adipogenesis.

Transplantation of CREG modified embryonic stem cells improves cardiac function after myocardial infarction in mice

Engraftment of embryonic stem cells (ESC) has been proposed as a potential therapeutic approach for post-infarction cardiac dysfunction. However, only mild function improvement has been achieved due to low survival rate and paracrine dysfunction of transplanted stem cells. Cellular repressor of E1A stimulated genes (CREG) has been reported to be a secreted glycoprotein implicated in promoting survival and differentiation of many cell types. Therefore we hypothesized that transplantation of genetically modified ESC with CREG (CREG-ESC) can improve cardiac function after myocardial infarction in mice. A total of 2 × 105 CREG-ESC or EGFP-ESC were engrafted into the border zone in a myocardial infarction model in mice. Cardiac function, infarct size and fibrosis at 4 weeks, survival of transplanted ESC, apoptosis and cytokine level of heart tissue, and teratoma formation were assessed in vivo. Apoptosis of ESC under inflammatory stimuli and cardiac differentiation of ESC were investigated in vitro. After 4 weeks, we found transplantation of CREG-ESC could significantly improve cardiac function, ameliorate cardiac remodeling, and reduce infarct size and fibrosis area. Transplantation of CREG-ESC remarkably increased ESC survival in the border zone and inhibited apoptosis of cardiomyocytes. Furthermore, the decrease of inflammatory factors (IL-1β, IL-6 and TNF-α) and increase of anti-inflammatory factors (TGF-β, bFGF and VEGF165) in the border zone were higher in CREG-ESC transplanted hearts. Safety evaluation showed that all transplantation at 2 × 105 per heart dose produced no teratoma. Surprisingly, the mice with 3.0 × 106 CREG-ESC transplantation was demonstrated teratoma free without cardiac rhythm disturbances in contrast to 100% teratoma formation and rhythm abnormality for the same dose of EGFP-ESC transplantation. In addition, overexpression of CREG inhibits ESC apoptosis and enhanced their differentiation into cardiomyocytes in vitro. Transplantation of CREG-modified ESC exhibits a favorable survival pattern in infarcted hearts, which translates into a substantial preservation of cardiac function after acute myocardial infarction.

Antiapoptotic role of the cellular repressor of E1A-stimulated genes (CREG) in retinal photoreceptor cells in a rat model of light-induced retinal injury

ObjectiveLight injury-induced apoptosis of retinal photoreceptor cells can lead to vision loss. The mechanism underlying such injury remains unclear, and there are no effective therapies at present. The aim of this study was to examine the potential antiapoptotic role of the cellular repressor of E1A-stimulated genes (CREG) in retinal cells in a rat model of light-induced retinal damage. MethodsCREG proteins were injected into the vitreous space of rats in which light retinal injury was induced. An equal volume of PBS was injected into the vitreous space of a control group. Retinas were collected for H&E staining and Western blotting analysis 1, 3, and 7 days later. Inhibitors or agonist for P38, JNK, and AKT were injected into the vitreous space to verify CREG function. ResultsIn rats with light-induced retinal injury, the CREG treatment inhibited the expression of apoptosis-related proteins caspase-3, caspase-8, and caspase-9 and signaling proteins phosphorylated ERK (P-ERK), phosphorylated JNK (P-JNK), phosphorylated P38 (P-P38), and phosphorylated AKT (P-AKT). An inhibitor of PI3K-AKT and an agonists of P38 and JNK abrogated the inhibitory effect of CREG on caspase-3 expression. ConclusionCREG protected retinal cells against apoptosis by inhibiting P38/MAPK and JNK/MAPK signaling pathways and activating the PI3K-AKT signaling pathway.

Hypoxia-Inducible Factor-1α (HIF-1α) Expression on Endothelial Cells in Juvenile Nasopharyngeal Angiofibroma: A Review of 70 cases and Tissue Microarray Analysis.

To examine the expression of hypoxia-inducible factor-1α (HIF-1α) and its related molecules (cellular repressor of E1A-stimulated genes [CREG], osteopontin [OPN], proto-oncogene tyrosine-protein kinase Src [c-Src], and vascular endothelial growth factor [VEGF]) in juvenile nasopharyngeal angiofibroma (JNA) and explore the correlation between clinical prognosis and HIF-1α expression. The study performed a retrospective review of the clinical records of patients with JNA treated between 2003 and 2007. Specimens were analyzed by immunohistochemistry for HIF-1α, CREG, OPN, c-Src, and VEGF expression, and microvessel density (MVD) was assessed by tissue microarray. The correlation between expression levels and clinicopathological features including age, tumor stage, intraoperative blood loss, and recurrence was analyzed. HIF-1α, CREG, OPN, c-Src, and VEGF were upregulated in endothelial cells (ECs) of patients with JNA, and strong correlations in the expression of these molecules were observed. HIF-1α expression was higher in young patients ( P = .032) and in recurrent cases ( P = .01). Survival analysis showed that low HIF-1α levels in ECs predicted longer time to recurrence (log rank test P = .006). Receiver operating characteristic curve analysis showed that HIF-1α was a prognostic factor for recurrence (area under the curve = 0.690, P = .019). No correlation was found between the expression of molecules and Radkowski stage or intraoperative blood loss. In cases of JNA treated surgically, HIF-1α expression in ECs is a useful prognostic factor for tumor recurrence.

Cellular Repressor of E1A-stimulated Genes, A New Potential Therapeutic Target for Atherosclerosis.

Atherosclerosis is a chronic inflammatory disease and a major risk factor for several important cardiovascular events, particularly coronary artery disease and stroke. The pathological process of atherosclerosis is considered to be dynamic and complicated, involving interactions between various different cell types within arteries and the cells that migrate into the vessel wall. Human cellular repressor of E1A-stimulated genes (CREG) was originally identified as a transcription factor with the ability to antagonize transcriptional activation and cellular transformation induced by the adenovirus E1A oncoprotein. However, subsequent studies also identified it as a secreted glycoprotein able to sustain cellular homeostasis and withstand pathological cell and tissue damage. We demonstrated that CREG may modulate homeostasis of vascular wall cells and inhibit inflammation of vascular tissue cells and macrophages, indicating a potential protective effect of CREG against inflammation. Mechanistically, CREG behaves like a typical soluble lysosomal protein that regulates the formation and maturation of lysosomes by modulating the small GTPase protein Rab7, to mediate autophagy in vascular tissue cells. The impact of CREG on lysosome formation may have important therapeutic significance in atherosclerosis.

GW28-e1131 Cellular Repressor of E1A-Stimulated Genes Protects from Myocardial Ischemia/Reperfusion Injury by Regulating Myocardial Autophagy and Apoptosis

Background: Cellular repressor of E1A-stimulated genes (Creg) is a secreted glycoprotein that regulates tissue and cell homeostasis and has been shown to antagonize heart injury; however, little is...

GW28-e1130 Cellular Repressor of E1A-stimulated Genes Promotes Smooth Muscle Cells Differentiation from Embryonic Stem Cells

GW28-e1130 Cellular Repressor of E1A-stimulated Genes Promotes Smooth Muscle Cells Differentiation from Embryonic Stem Cells

GW28-e1133 Cellular repressor of E1A-stimulated genes improves heart function in a mouse model of MI

GW28-e1133 Cellular repressor of E1A-stimulated genes improves heart function in a mouse model of MI

GW28-e1126 Cellular repressor of E1A-stimulated genes is a critical determinant of hypertensive vascular remodeling in response to angiotensin II

GW28-e1126 Cellular repressor of E1A-stimulated genes is a critical determinant of hypertensive vascular remodeling in response to angiotensin II

The novel intracellular protein CREG inhibits hepatic steatosis, obesity, and insulin resistance.

The results of our study provides evidence that CREG is a robust suppressor of hepatic steatosis and metabolic disorders through its direct interaction with ASK1 and the resultant inactivation of ASK1-JNK1 signaling. This study offers insights into NAFLD pathogenesis and its complicated pathologies, such as obesity and insulin resistance, and paves the way for disease treatment through targeting CREG. (Hepatology 2017;66:834-854).

CREG1 heterozygous mice are susceptible to high fat diet-induced obesity and insulin resistance.

Cellular repressor of E1A-stimulated genes 1 (CREG1) is a small glycoprotein whose physiological function is unknown. In cell culture studies, CREG1 promotes cellular differentiation and maturation. To elucidate its physiological functions, we deleted the Creg1 gene in mice and found that loss of CREG1 leads to early embryonic death, suggesting that it is essential for early development. In the analysis of Creg1 heterozygous mice, we unexpectedly observed that they developed obesity as they get older. In this study, we further studied this phenotype by feeding wild type (WT) and Creg1 heterozygote (Creg1+/-) mice a high fat diet (HFD) for 16 weeks. Our data showed that Creg1+/- mice exhibited a more prominent obesity phenotype with no change in food intake compared with WT controls when challenged with HFD. Creg1 haploinsufficiency also exacerbated HFD-induced liver steatosis, dyslipidemia and insulin resistance. In addition, HFD markedly increased pro-inflammatory cytokines in plasma and epididymal adipose tissue in Creg1+/- mice as compared with WT controls. The activation level of NF-κB, a major regulator of inflammatory response, in epididymal adipose tissue was also elevated in parallel with the cytokines in Creg1+/- mice. These pro-inflammatory responses elicited by CREG1 reduction were confirmed in 3T3-L1-derived adipocytes with CREG1 depletion by siRNA transfection. Given that adipose tissue inflammation has been shown to play a key role in obesity-induced insulin resistance and metabolic syndrome, our results suggest that Creg1 haploinsufficiency confers increased susceptibility of adipose tissue to inflammation, leading to aggravated obesity and insulin resistance when challenged with HFD. This study uncovered a novel function of CREG1 in metabolic disorders.

Cellular Repressor of E1A-Stimulated Genes Is a Critical Determinant of Vascular Remodeling in Response to Angiotensin II.

Cellular repressor of E1A-stimulated genes (CREG) is a lysosomal glycoprotein implicated in maintaining vascular homeostasis. Here, we have hypothesized that CREG is a critical target of intervention for the prevention of hypertensive vascular remodeling. CREG gene expression was significantly decreased accompanied by an upregulated expression of angiotensin II (Ang II) in remodeled vascular tissues of high salt-induced Dahl salt-sensitive rats and Ang II-induced mice. In particular, the downregulation of CREG gene was Ang II specific and independent from blood pressure. Prominent medial hypertrophy and vascular fibrosis in both thoracic aortas and mesenteric arteries were observed in CREG+/- mice infused with Ang II than in CREG+/+ mice, but blunted response in CREG+/+ mice received recombinant human CREG protein, suggesting that changes in CREG expression account for the different phenotype between genotypes. Within a tiled promoter array, E26 transformation-specific-1 binds to CREG promoter at high stringency with the stimulation of Ang II. Moreover, the Ang II-induced E26 transformation-specific-1 directly interacted with the CREG promoter (-1179 and -271 bp) and inhibited its transcription in vascular smooth muscle cells. Selective, pharmacological inhibition of E26 transformation-specific-1 led to restoration of CREG expression in aortas and rescue of experimental vascular remodeling by systemic administration of dominant negative E26 transformation-specific-1 membrane-permeable peptides. CREG is a novel mediator of vascular remodeling in response to Ang II and may be an attractive therapeutic target for prevention of vascular diseases.

CREG protects from myocardial ischemia/reperfusion injury by regulating myocardial autophagy and apoptosis

AimsHuman cellular repressor of E1A-stimulated genes (CREG) is a secreted glycoprotein that regulates tissue and cell homeostasis and has been shown to antagonize heart fibrosis, which indicates a potential protective effect of CREG against cardiomyocyte chronic damage. However, little is known about the role of CREG in myocardial tissue acute injury, in this study, we aimed to investigate the role of CREG in myocardial ischemia/reperfusion (MI/R) injury and clarify the mechanism of action. Methods and resultsWild-type Creg (Creg+/+), heterozygous Creg (Creg+/−) mice and mice pretreated with infusion of recombinant 0.3mg/kg·d CREG protein (reCreg+/+) were subjected to 30min of left ascending coronary ischemia and 24h of reperfusion. Evan's Blue-triphenyl- tetrazolium chloride (TTC) solution and echocardiography analysis were used to evaluate the effects of CREG on MI/R mice. The underlying mechanisms were further determined by cultured myocardial cells in vitro. Our findings revealed that the level of CREG protein in mouse hearts was significantly decreased after mice were subjected to MI/R. Moreover, Creg+/− mice had larger infarction size 2h after reperfusion and worse cardiac function 28days after MI/R injury compared to that in Creg+/+ mice. However, reCreg+/+ mice could maintain CREG at a high level even after MI/R injury, and mitigated infarction size and improved cardiac function significantly. In Creg+/− mice, myocardial autophagy was dysfunctional characterized by accumulation of LC3A and p62, while apoptotic cell number increase was detected by cleaved caspase-3 blotting and TUNEL staining. Conversely, decreased apoptosis and activated autophagy were detected in reCreg+/+ mice. Furthermore, chloroquine, a kind of autophagy blocker, was used to demonstrate recombinant CREG protected cardiomyocytes against apoptosis mediated by activating autophagy both in vivo and in vitro. Finally, we found CREG was involved into lysosomal protein transfer and improve cellular autophagy. ConclusionCREG protects heart against MI/R injury-induced cardiomyocytes apoptosis by activating lysosomal autophagy.This article is part of a Special Issue entitled: Genetic and epigenetic control of heart failure - edited by Jun Ren and Megan Yingmei Zhang.

Abstract 361: Creg1 Interacts With Sec8 to Promote Cell-cell Adhesion During Cardiomyogenesis

Cellular repressor of E1A-stimulated genes 1 (CREG1) is a 24 kD glycoprotein essential for early embryonic development. Our immunofluorescence studies revealed that CREG1 is highly expressed at myocyte junctions in both embryonic and adult hearts. To explore it role in cardiomyogenesis, we employed gain- and loss-of-function analyses demonstrating that CREG1 is required for the differentiation of mouse embryonic stem (ES) cell into cohesive myocardium-like structures. Chimeric cultures of wild-type and CREG1 knockout ES cells expressing cardiac-specific reporters showed that the cardiomyogenic effect of CREG1 is cell autonomous. Furthermore, we identified a novel interaction between CREG1 and Sec8 of the exocyst complex, which tethers vesicles to the plasma membrane. Mutations of the amino acid residues D141 and P142 to alanine in CREG1 abolished its binding to Sec8. To address the role of the CREG1-Sec8 interaction in cardiomyogenesis, we rescued CREG1 knockout ES cells with wild-type and Sec8-binding mutant CREG1 and showed that CREG1 binding to Sec8 promotes cardiomyocyte differentiation and cohesion. Mechanistically, CREG1, Sec8 and N-cadherin all localize at cell-cell adhesion sites. CREG1 overexpression enhances the assembly of adherens and gap junctions. By contrast, its knockout inhibits the Sec8-N-cadherin interaction and induces their degradation. Finally, shRNA-mediated knockdown of Sec8 leads to cardiomyogenic defects similar to CREG1 knockout. These results suggest that the CREG1 binding to Sec8 enhances the assembly of intercellular junctions and promotes cardiomyogenesis.

CREG1 Interacts with Sec8 to Promote Cardiomyogenic Differentiation and Cell-Cell Adhesion.

Understanding the regulation of cell-cell interactions during the formation of compact myocardial structures is important for achieving true cardiac regeneration through enhancing the integration of stem cell-derived cardiomyocytes into the recipient myocardium. In this study, we found that cellular repressor of E1A-stimulated genes 1 (CREG1) is highly expressed in both embryonic and adult hearts. Gain- and loss-of-function analyses demonstrated that CREG1 is required for differentiation of mouse embryonic stem (ES) cell into cardiomyocytes and the formation of cohesive myocardium-like structures in a cell-autonomous fashion. Furthermore, CREG1 directly interacts with Sec8 of the exocyst complex, which tethers vesicles to the plasma membrane. Site-directed mutagenesis and rescue of CREG1 knockout ES cells showed that CREG1 binding to Sec8 is required for cardiomyocyte differentiation and cohesion. Mechanistically, CREG1, Sec8, and N-cadherin colocalize at intercalated discs in vivo and are enriched at cell-cell junctions in cultured cardiomyocytes. CREG1 overexpression enhances the assembly of adherens and gap junctions. By contrast, its knockout inhibits the Sec8-N-cadherin interaction and induces their degradation. These results suggest that the CREG1 binding to Sec8 enhances the assembly of intercellular junctions and promotes cardiomyogenesis. Stem Cells 2016;34:2648-2660.

Up-Regulation of CREG Expression by the Transcription Factor GATA1 Inhibits High Glucose- and High Palmitate-Induced Apoptosis in Human Umbilical Vein Endothelial Cells.

BackgroundEndothelial 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.MethodsThe 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.ResultsCompared 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.ConclusionsThe 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.