Imaging RAGE expression in atherosclerotic plaques in hyperlipidemic pigs
© Johnson et al.; licensee Springer 2014
Received: 31 March 2014
Accepted: 29 April 2014
Published: 11 June 2014
Receptor for advanced glycated end product (RAGE) expression is a prominent feature of atherosclerosis. We have previously shown in apoE null mice uptake of a radiolabeled anti-RAGE antibody in atherosclerotic plaque and now evaluate RAGE-directed imaging to identify advanced plaques in a large animal model.
Nine hyperlipidemic (HL) pigs were injected with 603.1 ± 129.5 MBq of 99mTc-anti-RAGE F(ab′)2, and after 6 h (blood pool clearance), they underwent single-photon emission computed tomography/computed tomography (SPECT/CT) imaging of the neck, thorax, and hind limbs. Two HL pigs received 99mTc non-immune IgG F(ab′)2, and three farm pigs were injected with 99mTc-anti-RAGE F(ab′)2. After imaging, the pigs were euthanized. The aorta from the root to bifurcation was dissected, and the innominates, proximal carotids, and coronaries were dissected and counted, stained for H&E and RAGE, and AHA-classified.
On pathology, 24% of the arterial segments showed AHA class III or IV lesions, and these lesions were confined almost exclusively to coronaries and carotids with % stenosis from 15% to 65%. Scatter plots of %ID/g for class III/IV vs. I/II lesions showed almost complete separation. Focal vascular uptake of tracer visualized on SPECT scans corresponded to class III/IV lesions in the coronary and carotid vessels. In addition, uptake in the hind limbs was noted in the HL pigs and corresponded to RAGE staining of small arteries in the muscle sections. Correlations for the vascular lesions were r = 0.747, P = 0.001 for %ID vs. %ID/g and r = 0.83, P = 0.002 for %ID/g vs. % RAGE staining.
Uptake of radiolabeled anti-RAGE antibody in coronary and carotid fibroatheroma and in the small arteries of the hind limbs in a relevant large animal model of atherosclerosis supports the important role of RAGE in atherosclerosis and peripheral artery disease as a target for imaging and treatment.
KeywordsRAGE Atherosclerosis Hyperlipidemic pigs Imaging
Receptor for advanced glycation end products (RAGE) is a multi-ligand receptor that plays an important role in the initiation and progression of atherosclerotic plaque and in mediating vascular inflammation in a variety of conditions [,]. It is constitutively expressed in low levels on smooth muscle cells and endothelial cells in vascular endothelium, and the expression of RAGE increases in the vascular wall in response to a number of stimuli including hyperlipidemia and hyperglycemia [].
Studies investigating RAGE expression in mouse models of atherosclerosis have used tissue extracts for protein analysis and quantitative immunohistochemistry [,]. While these molecular biology tools are standard, they are limited in showing the extent and distribution of RAGE expression in the entire animal and require post-mortem tissue for analysis. Molecular imaging can show the distribution and intensity of the probe signal over the entire animal to identify the location and extent as well as the semi-quantitative expression of the target in an intact animal. This imaging approach is well suited to describe the expression of a receptor such as RAGE in atherosclerosis, a disease involving the entire arterial vascular tree.
We developed a radiolabeled monoclonal antibody fragment targeting a unique peptide sequence on the extracellular domain of the RAGE receptor and have shown in mouse models of atherosclerosis (apoE null) uptake on in vivo nuclear scans located in the sites of the atheroma in the aortic root and proximal aorta [,]. In developing a new radiotracer for possible clinical use, it is necessary to show the results of in vivo imaging in a large animal model. Swine are commonly used in cardiovascular research due to similarities in the coronary anatomy and cardiac function to that of humans. Hyperlipidemic pigs bred in the domestic swine background have become a useful large animal model of atherosclerosis []. The purpose of this study was to perform RAGE-directed SPECT imaging to test the hypothesis that the signal from the uptake of the radiolabeled probe in atheroma can be detected in a large animal model of atherosclerosis comparable to humans and to investigate the extent and distribution of RAGE expression in the arterial vascular tree and localize to atheroma.
This study was designed as a single group of hyperlipidemic (HL) pigs for two purposes: to evaluate the extent and severity of atherosclerosis and RAGE expression in this large animal model and to see whether the signal from a radiolabeled antibody coming from this receptor can be visualized on in vivo imaging and correlated with quantitative histomorphometry. Four farm pigs were used as disease control. Specificity was determined in two HL pigs injected with isotype control antibody. All animal experiments were performed with the approval of the Institutional Animal Care and Use Committee of Columbia University. Nine juvenile male LDL-deficient (Rapacz) swine were sent to us from the University of Wisconsin-Madison. Seven arrived at age 3 months and were maintained in house for approximately 9 months or to 1 year of age, and two HL pigs arrived at age 11 months and were maintained in house for 1 month. Four age- and weight-matched farm pigs were also studied for blood pool clearance and as disease controls for imaging and ex vivo well counting.
All pigs received a high-fat swine diet (15% lard, 1.2% cholesterol) (Harlan Teklad, Madison, WI, USA). Weights were obtained monthly, and on the same day, the animals were sedated for venous blood samples for fasting glucose, blood chemistry profile, and lipid profile.
The anti-RAGE antibody is a murine monoclonal antibody against the V-domain of RAGE designed to display immunoreactivity in mice, pigs, and human. The peptide sequence and production of the murine hybridoma has been described []. The monoclonal anti-RAGE antibody was fragmented using pepsin digestion into F(ab′)2 fragments (approximately 110 kDa) and immunoreactivity tested by ELISA using soluble RAGE antigen. Direct coupling of diethylenetriaminepentaacetic acid (DTPA) (bicyclic anhydride) to anti-RAGE F(ab′)2 antibody fragments for 99mTc labeling was performed as previously described [,]. The mean specific activity was 8.14 ± 3.8 MBq per microgram of protein, and the mean radiopurity was 98% ± 0.83% by instant thin-layer chromatography.
Blood pool clearance
Ear vein catheters were placed in both ears of four farm pigs. Into one ear vein, an average dose of 16 mCi of 99mTc-anti-RAGE F(ab′)2 was injected, and from the opposite ear vein, 1-ml samples were withdrawn at 2, 5, 10, 15, 20, 30, 45, 60, 90, 120, 180, 240, 300, and 360 min. From each tube, 50 μl was pipetted into pre-weighed tubes and counted in a gamma well counter. The counts vs. time were averaged for each time point and plotted. These pigs were also used for in vivo imaging and ex vivo well counting and histology.
Radiotracer injection and imaging
At approximately 1 year of age, each HL pig was sedated, and angiocatheters were placed in both ear veins. A dose of 16.3 ± 3.5 mCi (0.3 ± 0.1 mCi/kg, 658.6 ± 148.0 MBq, 63.6 ± 13.3 MBq/kg) of 99mTc-anti-RAGE F(ab′)2 antibody in 5-ml saline with a flush was injected through an ear vein. Two of these nine HL pigs also received 99mTc non-immune IgG(Fab′)2 as well as 99mTc-anti-RAGE F(ab′)2, 1-week apart with SPECT imaging following both injections, but the tissue was obtained after the control antibody. Four weight-matched farm pigs received injection of 99mTc-anti-RAGE (17.5 mCi, 0.4 mCi/kg, 653.7 MBq, 12.9 MBq/kg) and were imaged.
After injection, the pigs were awakened and returned to their cages for 5-6 h to allow for blood pool clearance, then were re-sedated, intubated, and transported to the imaging laboratory where they first underwent CT angiography followed by SPECT/CT imaging (Philips Precedence 16 slice Hybrid SPECT/CT, Philips Healthcare, Andover, MA, USA). Each pig was injected with 100-ml non-ionic iodinated contrast agent Optiray 320 (Covidien, Mansfield, MA, USA) through the ear vein following test bolus. Scouts comprised neck to abdomen/pelvis. The following acquisition protocol was used: 120 kV, tube current 337 mA, collimation 16 × 0.75 mm, pitch 0.688, and slice thickness 0.8 mm. Acquisition trigger was set for 180 HU at aortic arch. Following CT angiogram, hybrid SPECT/CT imaging was performed with bed positions to include the chest, neck, and hind limbs. Each SPECT scan was set for two heads mounted at 180° for 64 steps over 360°. At completion of the imaging, the pigs were returned to the necropsy suite of the Institute of Comparative Medicine and euthanized with a bolus of Euthasol (100 to 120 mg/kg IV; Virbac Animal Health, St. Louis MO, USA).
The SPECT scans were reconstructed using filtered back projection, and the CT and SPECT images blended using Syntegra software (Philips, Andover, MA, USA). Focal regions of tracer uptake were localized to the territory of the carotids on sagittal and coronal blended SPECT/CT scans, and regions of interest were drawn around the uptake on the coronal slices to comprise the area of focal uptake excluding the most cephalad and caudad slices to reduce partial volume effect, and the counts from these regions were summed and converted to %ID using measured camera efficiency values and decay times. Because of the very low myocardial uptake, focal hotspots in coronary artery territories were visualized and localized on the blended chest CTA/SPECT images (Syntegra). For the hind limbs, the ROIs were drawn around sequential 1-voxel thick transverse slices using the blended SPECT/CT to define limb boundaries from the proximal femur to the distal tibia/fibula, and the activity from all the slices were summed for each limb.
Necropsy and tissue preparation
The chest and abdomen were opened, the blood was drained from the vasculature, the heart was removed, and the coronaries from the opening of the coronary sinus to distal vessel were dissected out and rinsed with PBS. The aorta was dissected and removed from the aortic valve to beyond the iliac bifurcation to include the proximal femoral arteries and the major arch vessels (the brachiocephalic trunk (innominate artery) and carotid arteries). The tissue was cleaned and rinsed carefully and placed in a plastic tray kept moist in 10% formalin solution and placed on one of the detectors used for the in vivo scanning and imaged for 20 min. After imaging, representative cross-sections of the arteries were cut and labeled for well counting and sectioning. Each coronary was cut in four segments. The aorta was sampled as full-width cross-sectional segments from the aortic root through the abdominal aorta for a total of 12 segments per animal. The samples were taken from the proximal, mid, and distal innominate, from the proximal and mid right and left carotids, and from the proximal and mid femoral arteries. In addition, three samples were taken from each gastrocnemius muscle (six samples per pig). Each sample was weighed and counted in the gamma well counter (Wallac Wizard 1470, PerkinElmer, Waltham, MA, USA) along with an aliquot of the injected dose as standard and the %ID/g calculated for each sample and subsequently embedded in paraffin for sectioning. In selected animals, the lungs, liver, and heart were removed, weighed, and counted in the gamma well counter and then embedded in paraffin for sectioning.
For immunohistochemical analyses, serial sections were deparaffinized in xylene, treated with 0.3% hydrogen peroxide for 20 min, and incubated in protein-free block (Dako Inc., Carpinteria, CA, USA) for 10 min to inhibit the non-specific binding of primary antibody. All sections were stained with hematoxylin and eosin (H&E). Staining for RAGE was performed using monoclonal anti-RAGE antibody (50 μg/ml). Macrophages were identified using marker Mac-3 (1:20; BD Pharmingen, San Diego, CA, USA). Smooth muscle cells were identified using monoclonal mouse anti-human smooth muscle actin (1:50; Dako Inc.). Secondary staining was performed with HRP-conjugated respective secondary antibody, followed by diaminobenzidine (DAB substrate kit for peroxidase; Vector Laboratories, Burlingame, CA, USA), and counterstaining with Gill's hematoxylin solution.
Morphometric and immunohistochemical analyses of the arterial segments were performed using a Nikon microscope (Tokyo, Japan) and Image-Pro Plus software (Media Cybernetics Inc., Silver Spring, MD, USA). The lesion was measured as percent lesion area per total area of the aorta. RAGE staining was quantified as percent RAGE staining in the lesion area per total area of the aorta. Lesion morphology was classified according to the American Heart Association (AHA) criterion from class I to class IV [].
All data are presented as mean ± standard deviation. Correlation was assessed using the Pearson product–moment correlation.
Weights and blood tests
For the nine HL pigs, the average arrival weight was 26.1 ± 4.8 kg, and the final weight was 63.6 ± 12.3 kg. The average cholesterol levels at arrival and sacrifice were, respectively, 460.4 ± 93.1 mg/dL and 445.6 ± 72.4 mg/dL, triglyceride levels 54.1 ± 15.3 mg/dL and 47.1 ± 12.1 mg/dL, and fasting blood glucose 71.0 ± 9.3 mg/dL and 88.4 ± 20.9 mg/dL. The weight of the farm pigs at time of imaging averaged to 50.7 kg. All lab values for the farm pigs were within normal limits for species.
Blood pool clearance and biodistribution
Location and extent of atherosclerotic lesions on histopathology
Uptake of 99mTc-anti-RAGE F(ab′)2 in carotid and coronary arteries
Gamma well counting of vascular tissue
To better assess the relationship between tracer uptake and AHA class, all histological sections from the innominate, left and right carotid, LAD, RCA, LCx, aortic root, arch, and thoracic aorta for each animal were grouped into class I and II lesions (minimal disease) and class III and IV lesions (more advanced). The tracer uptake as %ID/g from well counting for these sections were plotted as scattergrams (Figure 5B). There was minimal overlap of values for the two groups. Only two vessels with minimal disease had an uptake of >3.5% ID/g × 10−4, and only one with advanced disease had an uptake of <3.5 (Figure 5B). The uptake in all class III and IV lesions in the coronary and carotid vessels was visible on the SPECT scans, and none of these vessels with only class I and II lesions showed focal tracer uptake.
Values for %ID for the visible focal vascular uptake of 99mTc-anti-RAGE F(ab′)2 were plotted vs. values for %ID/g for the same vascular segments counted on the gamma well counter. There was a significant correlation: r = 0.747, P < 0.001 (Figure 5C).
Quantitative staining of atheroma for RAGE
Quantitative immunostaining for RAGE as % vessel area ranged from 5% to 20% and localized to media and neointima. Serial sections stained for endothelial cells, macrophages, and smooth muscle cells showed predominant co-localization of RAGE staining with smooth muscle cells and macrophages (Figure 2). When % RAGE staining was plotted vs. vascular uptake of 99mTc-anti-RAGE F(ab′)2, there was a significant correlation: r = 0.824, P < 0.001.
Hind-limb uptake of anti-RAGE antibody
This paper is the first to report the potential value of imaging RAGE expression in atheroma throughout the vascular tree in a large animal model genetically altered to develop advanced atherosclerotic lesions similar in morphology to human disease [,-]. Using SPECT imaging, the focal uptake of a 99mTc-labeled probe binding RAGE was seen in the distribution of AHA class III and IV lesions in the carotid and coronary arteries. No focal uptake was seen in regions corresponding to class I and II lesions. These findings were confirmed by ex vivo well counting of the vascular tissue. In addition, diffuse uptake of RAGE targeting probe was seen in the lower extremities and histopathology showed increase RAGE expression in small- and medium-size arteries.
RAGE is a multi-ligand receptor that binds non-enzymatically glycosylated proteins or AGEs and other ligands initiating downstream pathways important in atherogenesis [-]. Knocking out RAGE in atherosclerotic-prone mice reduces the development of atherosclerosis [,], further supporting the importance of RAGE-initiated pathways in atherogenesis and plaque progression. Pathological studies of human autopsy or biopsy specimens have documented the importance of RAGE in atherosclerosis and peripheral artery disease. To localize and quantify RAGE expression, Burke et al. found RAGE expression in fibroatheromas from subjects with sudden cardiac death [], and Cipollone et al. found RAGE expression in carotid plaque from patients with transient ischemic events []. A pathology study reported by Ritthaler et al. in 1995 documented prominent enhancement of endothelial RAGE expression in small-and medium-size arteries in the lower extremities of patients with occlusive peripheral vascular disease [].
The development of both SPECT and PET probes targeting atherosclerosis towards the goal of finding a non-invasive screening test for subjects at highest risk for CV events (both myocardial infarction and stroke) has been a major focus for investigators in CV molecular imaging. As progress in molecular biology has identified an increasing number of potential sites for binding ligands, a large number of probes using nuclear, optical, ultrasound, and MR reporters have been developed for preclinical small animal studies []. Nuclear probes offer the advantage of small-size molecules that can gain access to the center of the lesion to bind to sites not accessible to larger probes that are confined to binding sites expressed on the vascular lining. The spatial resolution for the newer SPECT detectors even at the depth of the heart is at least twice the diameter of a coronary artery and PET resolution is at the border of the coronary diameter size. Despite limited resolution, focal uptake of tracers can be seen in small structures on in vivo scans as ‘beacons.’ The strength of the signal and ability to see it depend on the number of binding sites for the probe as well as attenuation and scatter from adjacent activity. Correlation with quantitative immunohistology allows us to identify a threshold level of target expression to permit in vivo imaging. The very fact that one can see this target indicates a high level of biological expression which would have clinical significance.
Hybrid imaging (SPECT/CT or PET/CT) when combined with angiography can optimize localization of focal tracer uptake to a vascular structure. Vascular uptake of 18 F-FDG tracks metabolic activity of plaque macrophages and therefore plaque inflammation, a pathological feature of vulnerability []. Because the myocardium relies on glucose as a substrate for metabolism, FDG has limited application for coronary imaging due to high background []. Carotid plaques are an easier target than coronary plaques due to larger size of vessels, less motion, and less attenuation. While focal uptake of FDG seen on PET/CT scans has been reported to correlate with plaque macrophages, limitations to 18 F-FDG carotid plaque imaging occur due to residual blood pool activity, adjacent tissue uptake, and effects of blood glucose levels on uptake []. While RAGE plays a role in a number of signaling pathways, its role in atherosclerosis is mediated mostly via inflammation pathways and, in this respect, similar to FDG. In contrast to FDG, 99mTc anti-RAGE F(ab′)2 probe has very low myocardial uptake due to low constitutive RAGE expression in the non-ischemic myocardium. Based on our experience with RAGE lung tissue staining in different species including human, the high lung uptake observed which interfered with imaging the aorta, is unique to the pig. The wide availability of hybrid imaging platforms as well as software for accurate registration of SPECT or PET scans with CT scans now makes it practical to apply hybrid nuclear/CT atherosclerotic plaque imaging as selective screening for very high risk patients.
The results of the current study documented in a large animal model of atherosclerosis with plaque characteristics similar to those of man that the focal uptake of a radiolabeled antibody targeting RAGE which plays an important role in atherogenesis and plaque vulnerability can be detected on in vivo imaging with a threshold for detection at AHA III and IV lesion severity. In addition, semi-quantitative uptake of tracer on in-vivo imaging localized to distribution of diseased coronary and carotid vessels correlated with gamma counting of the tissue and with quantitative staining for RAGE. Diffuse uptake of the radiolabeled tracer was seen in the hind limbs corresponding to RAGE expression in the small arteries. Because RAGE is a multi-ligand receptor and transduces many important signaling pathways in vascular disease and atherogenesis, it represents a potentially good target for imaging atherosclerosis and PAD.
The hybrid imaging would have been strengthened if we were able to perform coronary CT angiograms with gating to register with the SPECT images. We were unable to get the heart rates of the pigs low enough to permit good quality studies on a 16-slice CT scanner. While the whole body CTA we used to register with the SPECT to localize tracer uptake was ungated, the base of the heart where the origins of coronary arteries are located (Figure 3) has less cardiac motion than towards the apex, and any motion would serve only to further blur the focal hotspot but not reduce our sensitivity to detect it.
diethylene triamine pentaacetic acid:
high mobility group box 1:
left anterior descending:
receptor for advanced glycation end products:
right coronary artery:
regions of interest:
single-photon emission computed tomography/computed tomography:
LJ was the major contributor to the conception of the study; the design, analysis, and interpretation of data; and supervision of data acquisition. The funding for this project was awarded by NHLBI (RO1 HL089874) through the process of independent review with LJ as the PI. The effort on this project by all authors at CU (LJ, MK, YT, GE, and KB) were supported by the grant. Chong Li was supported by a student research stipend from University of Rochester. Christian Krueger and Dr. Shanmuganayagam provided the HL pigs and are supported by the University of Wisconsin, and Dr. Schmidt by an independent funding through the NIH.
- Schmidt AM, Yaan SD, Wautier J, Stern D: Activation of receptor for advanced glycation end products: a mechanism for chronic vascular dysfunction in diabetic vasculopathy and atherosclerosis. Circ Res 1999, 84: 489–497. 10.1161/01.RES.84.5.489View ArticlePubMedGoogle Scholar
- Yan SF, Ramasamy R, Schmidt AM: The RAGE axis: a fundamental mechanism signaling danger to the vulnerable vasculature. Circ Res 2010, 106: 842–853. 10.1161/CIRCRESAHA.109.212217PubMed CentralView ArticlePubMedGoogle Scholar
- Ramasamy R, Yan SF, Herold K, Clynes R, Schmidt AM: Receptor for advanced glycation end products fundamental roles in the inflammatory response: winding the way to the pathogenesis of endothelial dysfunction and atherosclerosis. Ann NY Acad Sci 2008, 1126: 7–13. 10.1196/annals.1433.056PubMed CentralView ArticlePubMedGoogle Scholar
- Harja E, Bu D-X, Hudson BI, Chang JS, Shen X, Hallam K, Kalea AZ, Lu Y, Rosario RH, Oruganti S, Nikolla Z, Belov D, Lalla E, Ramasamy R, Yan SF, Schmidt AM: Vascular and inflammatory stresses mediate atherosclerosis via RAGE and its ligands in apoE-/- mice. J Clin Invest 2008, 118: 183–194. 10.1172/JCI32703PubMed CentralView ArticlePubMedGoogle Scholar
- Wendt T, Harja E, Bucciarelli L, Qu W, Lu Y, Rong LL, Jenkins DG, Stein G, Schmidt AM, Yan SF: RAGE modulates vascular inflammation and atherosclerosis in a murine model of type 2 diabetes. Atherosclerosis 2006, 185: 70–77. 10.1016/j.atherosclerosis.2005.06.013View ArticlePubMedGoogle Scholar
- Tekabe Y, Li Q, Rosario R, Sedlar M, Majewski S, Hudson BI, Einstein AJ, Schmidt AM, Johnson LL: Development of RAGE-directed imaging of atherosclerosis plaque in a murine model of spontaneous atherosclerosis. Circ Cardiovasc Imaging 2008, 1: 212–219. 10.1161/CIRCIMAGING.108.788299View ArticlePubMedGoogle Scholar
- Tekabe Y, Luma J, Einstein AJ, Sedlar M, Qing L, Schmidt AM, Johnson LL: A novel monoclonal antibody for RAGE-directed imaging identifies accelerated atherosclerosis in diabetes. J Nucl Med 2010, 51: 92–97. 10.2967/jnumed.109.064659View ArticlePubMedGoogle Scholar
- Prescott MF, McBride CH, Hasler-Rapacz J, Linden JV, Rapacz J: Development of complex atherosclerotic lesions in pigs with inherited hyper-LDL cholesterolemia bearing mutant alleles for apolipoprotein B. Am J Pathol 1991, 139: 139–147.PubMed CentralPubMedGoogle Scholar
- Stary HC, Chandler B, Dinsmore RE, Fuster V, Glagov S, Insull W Jr, Rosenfield ME, Schwartz CJ, Wagner WD, Wissler R: A definition of advanced types of atherosclerotic lesions and a histological classification of atherosclerosis. Circulation 1995, 92: 1355–1374. 10.1161/01.CIR.92.5.1355View ArticlePubMedGoogle Scholar
- Rapacz J, Hasler-Rapacz J, Taylor KM, Checovidh WF, Attie AD: Lipoprotein mutations in pigs are associated with elevated plasma cholesterol and atherosclerosis. Science 1986, 234: 1573–1577. 10.1126/science.3787263View ArticlePubMedGoogle Scholar
- Checovich WJ, Fitch WL, Krauss RM, Smith MP, Rapazc J, Smith CL, Attie AD: Defective catabolism and abnormal composition of low-density lipoproteins from mutant pigs with hypercholesterolemia. Biochemistry 1988, 27: 1934–1941. 10.1021/bi00406a020View ArticlePubMedGoogle Scholar
- Lowe SW, Checovich WJ, Rapacz J, Attie AD: Defective receptor binding of low density lipoprotein from pigs possessing mutant apolipoprotein B alleles. J Biol Chem 1988, 263: 15467–15473.PubMedGoogle Scholar
- Hasler-Rapacz J, Ellegren H, Fridolfsson AK, Kirkpatrick B, Kirk S, Andersson L, Rapacz J: Identification of a mutation in the low density lipoprotein receptor gene associated with recessive familial hypercholesterolemia in swine. Am J Med Genet 1998, 76: 379–386. 10.1002/(SICI)1096-8628(19980413)76:5<379::AID-AJMG3>3.0.CO;2-IView ArticlePubMedGoogle Scholar
- Neeper M, Schmidt AM, Brett J, Yan SD, Wang F, Pan YC, Elliston K, Stern D, Shaw A: Cloning and expression of RAGE: a cell surface receptor for advanced glycosylation endproducts of proteins. J Biol Chem 1992, 267: 14998–15004.PubMedGoogle Scholar
- Schmidt AM, Yan SD, Brett J, Mora R, Nowygrad R, Stern D: Regulation of human mononuclear phagocyte migration by cell surface binding proteins for AGE. J Clin Invest 1993, 91: 2155–2168. 10.1172/JCI116442PubMed CentralView ArticlePubMedGoogle Scholar
- Kislinger T, Fu C, Huber B, Qu W, Taguchi A, DuYan S, Hofmann M, Yan SF, Pischetsrieder M, Stern D: Nε-(carboxymethyl) lysine adducts of proteins are ligands for receptor for advanced glycation endproducts that activate cell signaling pathways and modulate gene expression. J Biol Chem 1999, 274: 31740–31749. 10.1074/jbc.274.44.31740View ArticlePubMedGoogle Scholar
- Hofmann MA, Drury S, Fu C, Qu W, Taguchi A, Lu Y, Avila C, Kambham N, Bierhaus A, Newroth P, Neurath MF, Slattery T, Beach D, McClary J, Nagashima M, Moser J, Stern D, Schmidt AM: RAGE mediates a novel proinflammatory axis: a central cell surface receptor for S100/calgranulin polypeptides. Cell 1999, 97: 889–901. 10.1016/S0092-8674(00)80801-6View ArticlePubMedGoogle Scholar
- Arumugam T, Simeone DM, Schmidt AM, Logsdon CD: S100P stimulates cell proliferation and survival via receptor for advanced glycation endproducts (RAGE). J Bio Chem 2004, 279: 5059–5065. 10.1074/jbc.M310124200View ArticleGoogle Scholar
- Park L, Raman KG, Lee KJ, Yan L, Ferran LJ Jr, Chow WS, Stern D, Schmidt AM: Suppression of accelerated diabetic atherosclerosis by the soluble receptor for advanced glycation endproducts. Nat Med 1998, 1998: 1025–1031. 10.1038/2012View ArticleGoogle Scholar
- Bucciarelli LG, Wendt T, Qu W, Lu Y, Lalla E, Rong LL, Goova MT, Moser B, Kisinger T, Lee DC, Kashyap Y, Stern DM, Schmidt AM: RAGE blockade stabilizes established atherosclerosis in diabetic apolipoprotein E-null mice. Circulation 2002, 106: 2827–2835. 10.1161/01.CIR.0000039325.03698.36View ArticlePubMedGoogle Scholar
- Burke AP, Kolodgie FD, Zieske A, Fowler DR, Weber DK, Varghese PF, Farb A, Virmani R: Morphologic findings of coronary atherosclerotic plaques in diabetes. Arterioscler Thromb Biol 2004, 24: 1266–1271. 10.1161/01.ATV.0000131783.74034.97View ArticleGoogle Scholar
- Cipollone F, Iezzi A, Fazia M, Zucchelli M, Pini B, Cuccurullo C, DeCesare D, DeBlasis G, Muraro R, Bei R, Chiarelli F, Schmidt AM, Cuccurullo F: The receptor RAGE as a progression factor amplifying arachidonate-dependent inflammatory and proteolytic response in human atherosclerotic plaques: role of glycemic control. Circulation 2003, 108: 1070–1077. 10.1161/01.CIR.0000086014.80477.0DView ArticlePubMedGoogle Scholar
- Ritthaler U, Deng Y, Zhang Y, Greten J, Abel M, Sido B, Allenberg J, Otto G, Roth H, Bierhaus A, Ziegler R, Schmidt AM, Waldherr R, Wahl P, Stern DM, Nawroth PP: Expression of receptors for advanced glycation end products in peripheral occlusive vascular disease. Am J Pathol 1995, 146: 688–694.PubMed CentralPubMedGoogle Scholar
- Kusters DHM, Tegtmeier J, Schurgers LJ, Reutelingsperger CPM: Molecular imaging to identify the vulnerable plaque—from basic research to clinical practice. Mol Imaging Biol 2012, 14: 523–533. 10.1007/s11307-012-0586-7View ArticlePubMedGoogle Scholar
- Cheng VY, Slomka PJ, LeMeunier L, Tamaroppoo BK, Nakazato R, Dey D, Berman DS: Coronary arterial 18 F-FDG uptake by fusion of PET and coronary CT angiography at sites of percutaneous stenting for acute myocardial infarction and stable coronary artery disease. J Nucl Med 2012, 53: 575–583. 10.2967/jnumed.111.097550View ArticlePubMedGoogle Scholar
- Rudd JHF, Warburton TE, Fryer HA, Jones JC, Clark N, Antoun P, Johnstrom AP, Davenport PJ, Kirkpatrick BN, Arch JD, Pickard PL, Weissberg PL: Imaging atherosclerotic plaque inflammation with [18 F]-fluorodeoxyglucose positron emission tomography. Circulation 2002, 105: 2708–2711. 10.1161/01.CIR.0000020548.60110.76View ArticlePubMedGoogle Scholar
- Bucerius J, Mani V, Moncrieff C, Machac J, Fuster V, Farkouh ME, Tawakol A, Rudd JHF, Fayad ZA: Optimizing 18 F-FDG PET/CT imaging of vessel wall inflammation: the impact of 18 F-FDG circulation time, injected dose, uptake parameters, and fasting blood glucose levels. Eur J Nucl Med Mol Imaging 2014, 41: 369–383. 10.1007/s00259-013-2569-6PubMed CentralView ArticlePubMedGoogle Scholar
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