© 2003 by European Society of Cardiology
Copyright © 2003, European Society of Cardiology
Modulation of ERG25 expression by LDL in vascular cells
Cardiovascular Research Center, ICCC-CSIC, Hospital de la Santa Creu i Sant Pau, Avda. St. Antoni Maria Claret 167, 08025 Barcelona, Spain
* Corresponding author. Tel./fax: +34-93-291-9285. lbmucv{at}cid.csic.es
Received 21 October 2002; accepted 9 December 2002
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Abstract |
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Background: Plasma low density lipoproteins (LDL) play a key role in the pathogenesis of atherosclerosis. LDL modify gene expression in vascular cells leading to disturbances in the functional state of the vessel wall. Methods: Expression levels of C-4 sterol methyl oxidase gene (ERG25), sterol regulatory element binding protein (SREBP)-1 and -2 were evaluated in porcine aortic endothelial cells (PAEC), porcine and human smooth muscle cells (SMC) and in the vascular wall from normolipemic and hyperlipemic pigs by RT-PCR. SREBP-1 protein levels were assessed by Western blot and SREBP–SRE binding by EMSA. SREBP-2 was overexpressed by transient transfection with lipofectin. Results: We have identified expression of the ERG25 in vascular cells and analyzed its regulation by LDL. ERG25, an enzyme involved in cholesterol biosynthesis, is expressed in vascular endothelial and SMC from porcine and human origin and is downregulated by LDL in a time- and dose-dependent manner. Downregulation of ERG25 by LDL was abolished by an inhibitor of neutral cysteine proteases (N-acetyl-leucyl-leucyl-norleucinal) that abrogates SREBP catabolism. LDL downregulated SREBP-2 mRNA levels but not SREBP-1 expression in these cells and both ERG25 and SREBP-2 gene expression was significantly decreased in the vascular wall of diet-induced hypercholesterolemic swine. Finally, in cell transfection experiments SREBP-2 overexpression blocks ERG25 downregulation caused by LDL. Conclusions: Our results indicate that LDL modulate ERG25 expression in the vascular wall and suggest the involvement of SREBP-2 in this mechanism.
KEYWORDS Atherosclerosis; Endothelial function; Gene expression; Lipoproteins; Smooth muscle
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1 Introduction |
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Plasma LDL levels play a key role in the onset and progression of atherosclerosis [1]. This effect is mediated, at least in part, through the early modulation of gene expression in both endothelial and smooth muscle cells (SMC). In endothelial cells, LDL produce a decrease in nitric oxide bioavailability [2–5] and induce both cell adhesion molecule expression and leukocyte recruitment [6,7] among other effects. In addition, LDL induce mitogenic stimulus in SMC [10], activate SMC expression of proinflammatory factors like TNF-
[11] and transform these cells into foam cells by lipid accumulation [8,9]. The sterol regulatory element binding protein (SREBP) family of transcription factors is involved in the homeostasis of cholesterol and fatty acid metabolism in the liver and adipose tissue [12]. SREBP-2 is the isoform preferentially involved in cholesterol homeostasis while SREBP-1 controls fatty acid metabolism. These transcription factors are synthesized as precursors that remain associated to endoplasmic reticulum and nuclear membranes until sterol levels fall. Then a cascade of proteolytic reactions involving Site-1 and Site-2 proteases, release the mature form that migrates to the nucleus [13–15]. SREBPs regulate transcription of target genes by binding to conserved promoter motifs named sterol regulatory elements (SREs) [13]. We have analyzed the effect of LDL on the expression of both transcription factors and its target genes in vascular cells [5,16–18]. Although expression levels of SREBP-2 were reduced by LDL treatment [5], we have observed that LDL decrease endothelial expression of enzymes such as lysyl oxidase [16] and endothelial nitric oxide synthase (eNOS) [5] independently of SREBP-2 downregulation. In this work we have observed for the first time vascular C-4 sterol methyl oxidase (ERG25) expression. This gene involved in a postsqualene phase of cholesterol biosynthesis from 4,4-dimethylzymosterol to zymosterol, is downregulated by LDL both in vitro and in vivo by a SREBP-2-dependent mechanism.
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2 Methods |
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2.1 Cell culture
Porcine aortic endothelial cells (PAEC) were obtained from adult normolipemic animals as described [16]. Cells were grown in medium M199 (Gibco) supplemented with 10% fetal calf serum (FCS), antibiotics (0.1 mg/ml streptomycin, 100 U/ml penicillin G) and 2 mmol/l L-glutamine. Forty eight hours after plating, cells were placed in 2% FCS medium for 24 h. Then LDL (180 mg cholesterol/dl) were added for another 24 h. Human and porcine SMC were obtained by a modification of the explant technique as described [19,20]. SMC between passages 2 and 6 were grown until subconfluence. Then cells were arrested 48 h in M199 supplemented with 0.2% FCS and incubated with LDL for increasing times. Cell viability was determined by trypan blue exclusion.
2.2 Animals
Female pigs (body weight at initiation: 32±4 kg) were randomized into two groups: normolipemic animals (n = 6) which were fed with a normal chow and hyperlipidemic animals (n = 10) which were fed with a cholesterol-rich diet (2% cholesterol; 1% cholic acid; 20% beef tallow) for 100 days [21]. Plasma cholesterol levels and hematological parameters were measured at baseline and at sacrifice. Because atherosclerotic lesions develop initially in the abdominal aorta, rings of this vessel were collected and frozen in liquid N2 to measure gene expression. All procedures were in accordance with institutional guidelines and followed the American Physiological Society guidelines for animal research.
2.3 Plasma biochemistry
Plasma total cholesterol was determined with an automatic analyzer (Kodak Ektachem DT System). Plasma lipoproteins (HDL-cholesterol, LDL-cholesterol and VLDL-cholesterol) were fractionated using the validated methods of the Lipid Research Clinic Program [22] and quantified spectrophotometrically (Kontron Instruments).
2.4 LDL isolation
Porcine or human LDL were obtained from fresh plasma by sequential ultracentrifugation (d = 1.019–1.063 g/ml). LDL used in the experiments were <72 h old. The purity of LDL was assessed by agarose gel electrophoresis (Paragon System, Beckman). LDL samples had no detectable levels of endotoxin (Limulus Amebocyte Lysate test, Bio Whittaker) and thiobarbituric acid reactive substances values were below 1.5 nmol malonaldehyde/mg protein.
2.5 mRNA differential display analysis (mRNA-DD)
Total RNA was isolated using QuickPrepTM total RNA kit (Pharmacia) or UltraspecTM (Biotecx) according to the manufacturer. mRNA-DD analysis was performed with the DeltaTM RNA Fingerprinting kit (Clontech) as described previously [16]. PCR products were loaded on a denaturating 5% polyacrylamide/8 M urea in 0.5x TBE. Bands up- or downregulated by LDL were cut out and DNAs were eluted and reamplified with the same primers used in mRNA-DD. Reamplified products were cloned into the pGEM-TTM easy vector (Promega) and sequenced with the ABIPrism dRhodamine Terminator Cycle Sequencing kit (Perkin Elmer) and the T7 promoter sequencing primer (Promega). Comparison of DNA homology with databases (GenBank) was performed using BLAST.
2.6 RT-PCR analysis
ERG25, SREBP-1 and SREBP-2 mRNA levels were analyzed by RT-PCR. One µg of total RNA from control and LDL-treated cells was reverse transcribed [16]. The cDNA obtained was diluted 1:5. An aliquot of 2.5 µl of this dilution was amplified in a 25-µl reaction mixture containing: 2.5 µl PCR DIG labelling Mix (Roche Molecular Biochemicals), 1.3 U ExpandTM High Fidelity DNA polymerase (Roche Molecular Biochemicals) and 100 ng of each specific oligonucleotide in 1x buffer and 1.5 mmol/l MgCl2. The specific oligonucleotides selected were: 5'-ggc aag atg ctt tgg ttg tg-3' (ERG25 upper); 5'-tct cca gaa gca atg tta gc-3' (ERG25 lower); 5'-tgggaccattctgaccacaa-3' (SREBP-2 upper); 5'-gccacaggaggagagtctgg-3' (SREBP-2 lower); 5'-atgtagtcgatggccttgcg-3' (SREBP-1 upper) and 5'-tgtgacctcgcagatccagc-3' (SREBP-1 lower). Amplification was carried out by 20 (ERG25), 21 (SREBP-2) or 23 (SREBP-1) cycles of 94°C 1 min, 61°C 1 min and 72°C 2 min followed by a final extension of 72°C 7 min. Levels of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were used to normalize results. Detection of digoxigenin (DIG)-labelled nucleic acids was performed as described [16].
2.7 Western blot analysis
PAEC were incubated in the presence or in the absence of LDL (180 mg/dl) for 9 h. Whole-cell extracts (100 µg) were separated by SDS–PAGE (7.5%) and transferred to a nitrocellulose filter (Bio-Rad). Equal loading of protein in each lane was verified by Pounceau staining. Membranes were incubated with a rabbit polyclonal antibody against SREBP-1 (Santa Cruz Biotechnology) used at a dilution of 1:1000.
2.8 Electrophoretic mobility shift assay (EMSA)
The double-stranded DNA fragment corresponding to the SRE element present in the SREBP-2 promoter (positions –109 to –128) was used as a probe in EMSA. Nuclear extracts (10 µg) from PAEC were incubated for 15 min on ice with 1 µg of poly[d(I-C)] in 25 mmol/l Tris–HCl (pH 8), 4 mmol/l MgCl2, 5% glycerol, 0.5 mmol/l dithiothreitol, 0.5 mmol/l EDTA and 60 mmol/l KCl (final volume=20 µl). Then, 40,000 cpm of labelled SRE were added and incubation continued for an additional 30 min. DNA–protein complexes were resolved by electrophoresis and were detected by autoradiography.
2.9 Transient transfection
PAEC seeded on a six-well plate (180,000 cells/well), were transfected with the SREBP-2–NT expression vector (kindly provided by Dr. Müller-Wieland) that contains the active form of SREBP-2. Transient transfection assays were performed with 1 µg/well of either the SREBP-2–NT plasmid or the empty vector (pcDNA 3; Invitrogen) and 3 µl of lipofectin (Life Technologies). After 5 h of exposure to lipofectin, cells were washed and incubated for 32 h in 1% FCS medium. Then LDL (180 mg/dl) were added for another 7 h and ERG25 mRNA levels were analyzed by RT-PCR.
2.10 Statistical analysis
Data are expressed as mean±S.D. (unless stated). Multiple groups were compared by using ANOVA. For the in vivo study statistical differences between groups were analyzed by the Mann–Whitney U-test. Differences were considered significant at P<0.05.
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3 Results |
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3.1 ERG25 is expressed in endothelial cells and is downregulated by LDL
PAEC were incubated with atherogenic concentrations of LDL (180 mg/dl) for 24 h and cDNAs from control and LDL-treated cells were compared by mRNA-DD analysis. Twelve combinations of primers T and P were used with cells from different animals and with two dilutions of each cDNA. As shown in Fig. 1A a differential cDNA band was obtained with primers P4 and P7. This cDNA was cloned and sequenced showing high homology (95%) with the human ERG25 gene. Downregulation of ERG25 gene expression by LDL was confirmed by RT-PCR analysis. ERG25 mRNA levels decreased about 14-fold by LDL treatment (1±0.49 vs. controls: 14.3±5) (Fig. 1B). The effect of LDL on ERG25 expression was time- and dose-dependent. The decrease in ERG25 mRNA levels was observed after 4 h of incubation with the highest concentration tested (180 mg/dl) (Fig. 2A). A pronounced reduction was observed even at the smallest concentration assayed after longer incubation times (24 h) (Fig. 2B). ERG25 downregulation by LDL was also observed in SMC from both porcine (Fig. 3) and human origin (data not shown).
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), SREBP-1 (
) and -2 (
) mRNA levels were analyzed by RT-PCR and normalized by GAPDH mRNA levels. Results come from two experiments performed in duplicate.3.2 SREBP-1 and -2 mRNA levels in vascular cells and in the arterial wall
We analyzed both SREBP-1 and SREBP-2 mRNA levels in PAEC. SREBP-2 mRNA levels were decreased by LDL in a dose- (Fig. 4A) and time-dependent manner (Fig. 4B). By contrast, SREBP-1 mRNA levels (Fig. 4A and B) and protein (Fig. 4C) were unchanged by LDL. Similar results were obtained in SMC from pigs (Fig. 3) and humans (data not shown). Since LDL downregulate ERG25 mRNA levels in both vascular SMC and endothelial cells, we analyzed ERG25 expression in abdominal aorta from normolipemic and hypercholesterolemic animals. The hypercholesterolemic diet increased plasma LDL concentrations (333±120 vs. 34±10.9 in normolipemics; P<0.01) and as shown in Fig. 5 both ERG25 and SREBP-2 mRNA levels were significantly lower in the aorta of hypercholesterolemic animals than in normolipemics (2.31±1.6 vs. 7±2.6; P<0.05).
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3.3 SREBP-2 is involved in ERG25 downregulation caused by LDL
Downregulation of ERG25 expression by LDL was abrogated by ALLN (25 µmol/l), an inhibitor of cysteine proteases that blocks SREBP catabolism (Fig. 6A) [13], suggesting that SREBPs should be involved in this effect. To test this hypothesis, PAEC were incubated with LDL (180 mg/dl, 9 h) and nuclear extracts from control and LDL-treated cells were prepared. As shown in Fig. 6B nuclear extracts from LDL-treated cells showed a lower binding capacity to an SRE element than control ones, while the binding to an unrelated probe (Oct I) was unaffected. Since SREBP-2 was the isoform regulated by LDL, we analyzed the effect of transcriptionally active SREBP-2 overexpression on ERG25 expression. As shown in Fig. 7, the downregulatory effect caused by LDL on ERG25 expression was abrogated in PAEC transfected with a plasmid (SREBP-2–NT) that expresses the mature form of SREBP-2.
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4 Discussion |
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Atherogenic levels of LDL are one of the most important risk factors in atherosclerosis. Hypercholesterolemia induces changes in vascular cell gene expression leading to alterations in vascular function [23–25]. By means of mRNA-DD we have identified for the first time the expression of ERG25 in vascular cells. ERG25 catalyzes the demethylation of 4,4-dimethylzymosterol leading to the synthesis of zymosterol [26], an intermediary in the biosynthesis of cholesterol. This enzyme is a membrane protein that seems to be associated with both the endoplasmic reticulum and the cell surface. Recently, the ERG25 gene has been cloned in yeast, humans [27] and fungi [28] but little is known about its regulation. Here we show that LDL downregulate ERG25 mRNA levels in the vascular wall and our data suggest the involvement of SREBP-2 in this effect.
ALLN reverted the downregulation of ERG25 mRNA levels produced by LDL. ALLN, an unspecific inhibitor of cysteine proteases, has been described as an SREBP catabolism inhibitor [13,29], thus, SREBPs seem involved in LDL effects. SREBPs regulate several cholesterogenic enzymes in liver, like HMG-CoA reductase, HMG-CoA synthase and farnesyl diphosphate synthase [30–32]. We show that SREBP-2, the isoform involved preferentially in liver cholesterol homeostasis [12], is downregulated by LDL in vascular endothelial and smooth muscle cells. On the contrary, SREBP-1 mRNA levels and both mature and precursor forms of SREBP-1 were not modified by LDL treatment in these cells.
Interestingly, both the ERG25 and SREBP-2 downregulation was also observed in vivo in aortic samples from hypercholesterolemic pigs. Thus, we have observed a parallel regulation of SREBP-2 and ERG25 mRNA levels both in vitro and in the vascular wall. A coordinated regulation of genes encoding enzymes involved in the first steps of cholesterol biosynthesis has been described in different cell types under a variety of conditions including LDL treatment [33,34]. Recent findings in different systems attribute a major role to SREBP-2, that itself is regulated by LDL, in this coordinate regulation [35,36]. However, no information on the effect of LDL on other key enzymes of the cholesterol pathway in vascular tissues is available.
Besides a transcriptional regulation of SREBP-2 itself [37], a proteolytic processing has been described as a regulatory mechanism for SREBPs [14]. Although the proteolytic hypothesis establishes that the content of nuclear SREBPs would depend basically on the proteolytic activity, recently, different authors have observed that the levels of both the nuclear form (active) and the precursor (inactive) form of SREBPs change in parallel to the SREBP mRNA levels [38,39]. Protein SREBP-2 levels could not be measured by Western blot, due to the low efficiency of commercially available antibodies. However, since nuclear SREBP-1 levels were unchanged by LDL, the changes in SREBP-2 mRNA levels observed both in vitro and in vivo may be associated to the decrease in SRE-binding activity observed by EMSA. In addition, overexpression of the active SREBP-2 form blocks the ERG25 downregulation caused by LDL supporting the involvement of this transcription factor in the LDL-mediated effect. Our results are in agreement with recent data from SREBP-1 and SREBP-2 transgenic mice suggesting that in liver ERG25 expression is preferentially regulated by SREBP-2 [40].
In summary, our present data show the downregulation of ERG25 by LDL, in vascular cells in culture and in vivo in the vascular wall. High levels of cholesterogenic enzymes are needed in non-hepatic tissues with high cell growth rates or that synthesize steroid hormones, but it has been surprising to find significant basal expression levels of this enzyme in the vascular wall. Thus, the cholesterogenic pathway may be important in the regulation of cell homeostasis and function in vascular tissues. The disturbance of the regulation of lipid metabolism in the vascular wall cells could be directly involved in the pathologic changes associated to the development of atherosclerotic lesions and may represent new local targets for pharmacological intervention.
Time for primary review 23 days.
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Acknowledgements |
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This study has been possible thanks to funds provided by MSD, Spain, PN-SAF 2000/0174 and FIC-Catalana Occidente. The authors are indebted to the technical assistance provided by Olga Bell, Pablo Catalina and Silvia Aguiló. B. Raposo and G. Vilahur are predoctoral fellows of CSIC and FIS, respectively.
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References |
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TopAbstract1 Introduction2 Methods3 Results4 DiscussionReferences |
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- Fuster V., Badimon L., Badimon J.J., Chesebro J.H. The pathogenesis of coronary artery disease and the acute coronary syndromes (part I). N Engl J Med (1992) 326:242–250.[Web of Science][Medline]Fuster V., Badimon L., Badimon J.J., Chesebro J.H. The pathogenesis of coronary artery disease and the acute coronary syndromes (part II). N Engl J Med (1992) 326:310–318.[Web of Science][Medline]
- Vidal F., Colomé C., Martínez-González J., Badimon L. Atherogenic concentrations of native low-density lipoproteins down-regulate nitric-oxide-synthase mRNA and protein levels in endothelial cells. Eur J Biochem (1998) 252:378–384.[Web of Science][Medline]
- Zhu Y., Liao H.L., Wang N., et al. Lipoprotein promotes caveolin-1 and ras translocation to caveola: role of cholesterol in endothelial signalling. Arterioscler Thromb Vasc Biol (2000) 20:2465–2470.
[Abstract/Free Full Text] - Boger R.H., Sydow K., Borlak J., et al. LDL cholesterol upregulates synthesis of asymmetrical dimethylarginine in human endothelial cells: involvement of S-adenosylmethionine-dependent methyltransferases. Circ Res (2000) 87:99–105.
[Abstract/Free Full Text] - Martínez-González J., Raposo B., Rodríguez C., Badimon L. HMG-CoA reductase inhibition prevents eNOS downregulation by atherogenic levels of native LDL: balance between transcriptional and post-transcriptional regulation. Arterioscler Thromb Vasc Biol (2001) 21:804–809.
[Abstract/Free Full Text] - Smalley D.M., Lin J.H.C., Curtis M.L., et al. Native LDL increases endothelial cell adhesiveness by inducing intercellular adhesion molecule-1. Arterioscler Thromb Vasc Biol (1996) 16:585–590.
[Abstract/Free Full Text] - Allen S., Khan S., Al-Mohanna F., Battern P., Yacoub M. Native low density lipoprotein-induced calcium transients trigger VCAM-1 and E-selectin expression in cultured human vascular endothelial cells. J Clin Invest (1998) 101:1064–1075.[Web of Science][Medline]
- Campbell J.H., Campbell G.R. The role of smooth muscle cells in atherosclerosis. Curr Opin Lipidol (1994) 5:323–330.[Medline]
- Niemann-Jonsson A., Dimayuga P., Jovinvge S., et al. Accumulation of LDL in rat arteries is associated with activation of tumor necrosis factor-alpha expression. Arterioscler Thromb Vasc Biol (2000) 20:2205–2211.
[Abstract/Free Full Text] - Stein O., Stein Y. Smooth muscle cells and atherosclerosis. Curr Opin Lipidol (1995) 6:269–274.[Web of Science][Medline]
- Llorente-Cortés V., Martínez-González J., Badimon L. LDL receptor-related protein mediates uptake of aggregated LDL in human vascular smooth muscle cells. Arterioscler Thromb Vasc Biol (2000) 20:1572–1579.
[Abstract/Free Full Text] - Horton J.D., Shimomura I. Sterol regulatory element-binding proteins: activators of cholesterol and fatty acid biosynthesis. Curr Opin Lipidol (1999) 10:143–150.[CrossRef][Web of Science][Medline]
- Wang X., Sato R., Brown M.S., Hua X., Goldstein J.L. SREBP-1, a membrane-bound transcription factor released by sterol-regulated proteolysis. Cell (1994) 77:53–62.[CrossRef][Web of Science][Medline]
- Brown M.S., Goldstein J.L. A proteolytic pathway that controls the cholesterol content of membranes, cells and blood. Proc Natl Acad Sci USA (1999) 96:11041–11048.
[Abstract/Free Full Text] - Russell A., Boyd D., Brown M.S., et al. Transport-dependent proteolysis of SREBP: relocation of site-1 protease from golgi to ER obviates the need for SREBP transport to golgi. Cell (1999) 99:703–712.[CrossRef][Web of Science][Medline]
- Rodríguez C., Raposo B., Martínez-González J., Casaní L., Badimon L. Low density lipoprotein downregulate lysyl oxidase in vascular endothelial cells and in the arterial wall. Arterioscler Thromb Vasc Biol (2002) 22:1409–1414.
[Abstract/Free Full Text] - Rodríguez C., Martínez-González J., Sánchez-Gómez S., Badimon L. LDL downregulate CYP51 in porcine vascular endothelial cells and in the arterial wall through a sterol regulatory element binding protein-2-dependent mechanism. Circ Res (2001) 88:268–274.
[Abstract/Free Full Text] - Martínez-González J., Rius J., Badimon L. A nuclear orphan receptor identified in human atherosclerotic plaques is induced by LDL. Atherosclerosis (2000) 151:178. Abstract.
- Martínez-González J., Badimon L. Human and porcine smooth muscle cells share similar proliferation dependence on the mevalonate pathway: implications for in vivo interventions in the porcine model. Eur J Clin Invest (1996) 26:1023–1032.[CrossRef][Web of Science][Medline]
- Llorente-Cortés V., Martínez-González J., Badimon L. Esterified cholesterol accumulation induced by aggregated LDL uptake in human vascular smooth muscle cells is reduced by HMG-CoA reductase inhibitors. Arterioscler Thromb Vasc Biol (1998) 18:738–746.
[Abstract/Free Full Text] - Alfon J., Royo T., García-Moll X., Badimon L. Platelet deposition on eroded vessel wall at stenotic shear rate is inhibited by lipid-lowering treatment with atorvastatin. Arterioscler Thromb Vasc Biol (1999) 19:1812–1817.
[Abstract/Free Full Text] - Lipid Research Clinic Program. Manual of laboratory operation. DHEW publ. no. NIH75-628. (1974) Washington, DC: US Government Printing Office. May.
- Li H., Cybulsky M.I., Gimbrone M.A., Libby P. An atherogenic diet rapidly induces VCAM-1, a cytokine-regulatable mononuclear leukocyte adhesion molecule, in rabbit aortic endothelium. Arterioscler Thromb (1993) 13:197–204.
[Abstract/Free Full Text] - Zeiher A.M., Drexler H., Wollschlager H., Just H. Modulation of coronary vasomotor tone in humans. Progressive endothelial dysfunction with different early stages of coronary atherosclerosis. Circulation (1991) 83:391–401.
[Abstract/Free Full Text] - Casino P.R., Crescence M.K., Quyyumi A.A., Hoeg J.M., Panza J.A. The role of nitric oxide in endothelium-dependent vasodilation of hypercholesterolemic patients. Circulation (1993) 88:2541–2547.
[Abstract/Free Full Text] - Bard M., Bruner D.A., Pierson C.A., et al. Cloning and characterization of ERG25, the Saccharomyces cerevisiae gene encoding C-4 sterol methyl oxidase. Proc Natl Acad Sci USA (1996) 93:186–190.
[Abstract/Free Full Text] - Li L., Kaplan J. Characterization of yeast methyl sterol oxidase (ERG25) and identification of a human homologue. J Biol Chem (1996) 271:16927–16933.
[Abstract/Free Full Text] - Kennedy M.A., Johnson T.A., Lees N.D., et al. Cloning and sequencing of the Candida albicans C-4 sterol methyl oxidase gene (ERG25) and expression of an ERG25 conditional lethal mutation in Saccharomyces cerevisiae. Lipids (2000) 35:257–262.[Web of Science][Medline]
- Yang J., Sato R., Goldstein J.L., Brown M.S. Sterol-resistant transcription in CHO cells caused by gene rearrangement that truncates SREBP-2. Genes Dev (1994) 8:1910–1919.
[Abstract/Free Full Text] - Goldstein J.L., Brown M.S. Regulation of the mevalonate pathway. Nature (1990) 343:425–430.[CrossRef][Medline]
- Osborne T.F. Transcriptional control mechanisms in the regulation of cholesterol balance. Crit Rev Eukaryot Gene Expr (1995) 5:317–335.[Web of Science][Medline]
- Ericsson J., Jackson S.M., Lee B.C., Edwards P.A. Sterol regulatory element binding protein binds to a cis element in the promoter of the farnesyl diphosphate synthase gene. Proc Natl Acad Sci USA (1996) 93:945–950.
[Abstract/Free Full Text] - Rossert D.S., Ashby M.N., Ellist J.L., Edwards P.A. Coordinate regulation of 3-hydroxy-3-methylglutaryl-coenzyme A synthase, 3-hydroxy-3-methylglutaryl-coenzyme A reductase and prenyltransferase synthesis but not degradation in HepG2 cells. J Biol Chem (1989) 264:12653–12656.
[Abstract/Free Full Text] - Chang T.Y., Limanek J.S. Regulation of cytosolic acetoacetyl coenzyme A thiolase, 3-hydroxy-3-methylglutaryl-coenzyme A synthase, 3-hydroxy-3-methylglutaryl-coenzyme A reductase and mevalonate kinase by low density lipoprotein and by 25-hydroxycholesterol in chinese hamster ovary cells. J Biol Chem (1980) 255:7787–7795.
[Free Full Text] - Harris I.R., Farrel A.M., Holleran W.M., et al. Parallel regulation of sterol regulatory element binding protein-2 and the enzymes of cholesterol and fatty acid synthesis but not ceramide synthesis in cultured human keratinocytes and murine epidermis. J Lipid Res (1998) 39:412–422.
[Abstract/Free Full Text] - Pai J., Guryev O., Brown M.S., Goldstein J.L. Differential stimulation of cholesterol and unsaturated fatty acid biosynthesis in cells expressing individual nuclear sterol regulatory element-binding proteins. J Biol Chem (1998) 273:26138–26148.
[Abstract/Free Full Text] - Sato R., Inoue J., Kawabe Y., Kodama T., Takano T., Maeda M. Sterol-dependent transcriptional regulation of sterol regulatory element-binding protein-2. J Biol Chem (1996) 271:26461–26464.
[Abstract/Free Full Text] - Field J.F., Born E., Murthy S., Mathur S.N. Regulation of sterol regulatory element-binding proteins in hamster intestine by changes in cholesterol flux. J Biol Chem (2001) 276:17576–17583.
[Abstract/Free Full Text] - Kim H.J., Takahashi M., Ezaki O. Fish oil feeding decreases mature sterol regulatory element-binding protein 1 (SREBP-1) by downregulation of SREBP-1c mRNA in mouse liver. J Biol Chem (1999) 274:25892–25898.
[Abstract/Free Full Text] - Tacer K.F., Haugen T.B., Baltsen M., Debeljak N., Rozman D. Tissue-specific transcriptional regulation of the cholesterol biosynthetic pathway leads to accumulation of testis meiosis-activating sterol (T-MAS). J Lipid Res (2002) 43:82–89.
[Abstract/Free Full Text]
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L. Zeng, H. Liao, Y. Liu, T.-S. Lee, M. Zhu, X. Wang, M. B. Stemerman, Y. Zhu, and J. Y.-J. Shyy Sterol-responsive Element-binding Protein (SREBP) 2 Down-regulates ATP-binding Cassette Transporter A1 in Vascular Endothelial Cells: A NOVEL ROLE OF SREBP IN REGULATING CHOLESTEROL METABOLISM J. Biol. Chem., November 19, 2004; 279(47): 48801 - 48807. [Abstract] [Full Text] [PDF]
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 J. Rius, J. Martinez-Gonzalez, J. Crespo, and L. Badimon Involvement of Neuron-Derived Orphan Receptor-1 (NOR-1) in LDL-Induced Mitogenic Stimulus in Vascular Smooth Muscle Cells: Role of CREB Arterioscler Thromb Vasc Biol, April 1, 2004; 24(4): 697 - 702. [Abstract] [Full Text] [PDF]
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