Microarray Analysis Reveals Overexpression of CD163 and HO-1 in Symptomatic Carotid Plaques

Abstract

Objective-We studied by microarray analysis whether symptomatic and asymptomatic carotid plaques from the same patient differ in gene expression and whether the same changes are present in an independent sample set. Methods and Results-Carotid plaques from four patients with bilateral high-grade stenosis, one being symptomatic and the other asymptomatic, were analyzed on Affymetrix U95Av2 arrays. 33 genes showed Ͼ1.5-fold change between symptomatic and asymptomatic plaques in an intraindividual comparison with FDR ranging from 0.28 to 0.40. Three genes involved in iron-heme homeostasis, CD163, HO-1, and transferrin receptor, were further analyzed in 40 independent plaques. HO-1 (fold-change 1.93, 95%CI 1.04 to 3.94, Pϭ0.040) and CD163 (1.58, 1.11 to 2.40, Pϭ0.013) mRNAs were again induced, and also HO-1 protein was overexpressed in symptomatic plaques (4.38, 1.54 to 12.20, Pϭ0.024). The expression of HO-1 and CD163 correlated with tissue iron content but iron itself was not associated with the symptom status. Conclusions-Symptomatic plaques show overexpression of CD163 and HO-1 both in intraindividual and interindividual comparison. Their expression correlates with iron deposits but asymptomatic and symptomatic plaques from isolated patients do not differ in macroscopic hemorrhages or iron deposits. We suggest that symptomatic plaques show a more pronounced induction of CD163 and HO-1 in response to plaque hemorrhages. Key Words: atherosclerosis Ⅲ carotid arteries Ⅲ gene expression Ⅲ microarray Ⅲ stroke S evere atherosclerotic narrowing of the internal carotid artery was found in 20% to 30% of patients with ischemic stroke in its supply territory. 1 Features associated with a symptomatic plaque include the degree of vessel stenosis, prior symptoms, and plaque characteristics, such as ulceration, inflammatory cell infiltration, and a thin fibrous cap. [2][3][4] However, these characteristics are poor predictors of the risk of thromboembolism and, as a result, 80% of patients undergoing carotid endarterectomy are needlessly exposed to surgical risks. 1 Thus better markers for the symptom causing carotid disease are needed. See coverMicroarray technology provides a rapid means to screen gene expression in the tissues of interest. Several efforts have been made to study large-scale gene expression in human atherosclerosis, for example by comparing gene expression in normal and atherosclerotic arteries. 5,6 Changes involved in destabilization of the atherosclerotic plaque have been less in focus. [7][8][9] Whereas symptomatic high-grade carotid plaque remains highly susceptible to recurrent ipsilateral symptoms, the risk of stroke from contralateral asymptomatic plaque is low, comparable to that of asymptomatic carotid stenosis in general. 10 Thus intraindividual differences in the carotid stenoses exist in the same patient causing one plaque to become symptomatic and the other to remain silent. The causes of these differences are unknown. This led us to a microarray study on patients operated due to bilateral sig...

Adipophilin Expression Is Increased in Symptomatic Carotid Atherosclerosis

“…The mean adipophilin protein expression also associated with the macrophage count (rϭ0.379, Pϭ0.001), and with the amount of CD163 mRNA (rϭ0.215, Pϭ0.048) in these CPs as determined previously. 5,10 In addition, it associated positively with the degree of CP stenosis (rϭ0.269, Pϭ0.014) and negatively with the presence of endothelium, as found previously 9 …”

“…It further associated with the amount of CD163 mRNA (r s ϭ0.677, PϽ0.001) and HO-1 mRNA (r s ϭ0.751, PϽ0.001), as assessed previously. 5 Men had clearly more intense ADFP mRNA expression (Mann-Whitney U: Pϭ0.035), patients with diabetes (Mann-Whitney U: Pϭ0.005) or hypertension (Mann-Whitney U: Pϭ0.022) had more ADFP mRNA, but no other risk factors of atherosclerosis (eg, age, smoking, BMI, coronary disease, peripheral artery disease, dyslipidemia, medication, or time delay between symptom and surgery) had any associations with ADFP mRNA expression.…”

“…4 Based on our previous DNA microarray analysis, we concluded that ADFP (the adipophilin gene) belongs to the set of genes induced selectively in symptomatic carotid plaques (CP) compared with asymptomatic CPs showing 1.7-fold induction in symptomatic plaques. 5 Adipophilin, an adipose differentiation-related protein, is found in lipidcontaining cells, 6 including macrophage foam cells. Its expression in macrophages is enhanced by modified LDL, 7 and when expressed, it further enhances lipid accumulation and prevents lipid efflux from lipid-laden macrophages.…”

An Imbalance Between CD36 and ABCA1 Protein Expression Favors Lipid Accumulation in Stroke-Prone Ulcerated Carotid Plaques

“…4,5 Quantitative real-time reverse-transcription polymerase chain reaction was performed using Assays-on-Demand Gene Expression Products and an ABI PRISM 7000 Sequence Detection System (Applied Biosystems). Relative CD36 and ABCA1 gene expression was determined using the comparative CT method and standard curve method, respectively, and expression of ␤-actin was used for normalization.…”

Prediction of Ischemic Events on the Basis of Transcriptomic and Genomic Profiling in Patients Undergoing Carotid Endarterectomy

“…Online address: http://www.molmed.org doi: 10.2119/molmed.2011.00479 tients, healthy controls and patients with thoracic aortic aneurysm, as well as patients differing in their extent of coronary artery disease (6)(7)(8)(9)(10). Other studies have examined diseased tissue biopsied from the site of disease, with a similar aim of identifying disease-specific gene expression (11)(12)(13)(14)(15). Although many such disease-specific differences in gene expression profiles have been noted to be present at the time of sampling, it is unknown whether expression patterns predict future prognosis.…”