Association between Pericytes in Intraplaque Neovessels and Magnetic Resonance Angiography Findings.

Atsushi Ogata,Tatsuya Tanaka,Tomihiro Wakamiya,Tatsuya Abe,Shuji Sakata,Masashi Nishihara,Nobuaki Momozaki,Hiroyuki Irie,Jun Masuoka,Taichiro Mizokami

doi:10.3390/ijms21061980

Abstract

(1) Background: Pericytes are involved in intraplaque neovascularization of advanced and complicated atherosclerotic lesions. However, the role of pericytes in human carotid plaques is unclear. An unstable carotid plaque that shows high-intensity signals on time-of-flight (TOF) magnetic resonance angiography (MRA) is often a cause of ischemic stroke. The aim of the present study is to examine the relationship between the pericytes in intraplaque neovessels and MRA findings. (2) Methods: A total of 46 patients with 49 carotid artery stenoses who underwent carotid endarterectomy at our hospitals were enrolled. The patients with carotid plaques that were histopathologically evaluated were retrospectively analyzed. Intraplaque hemorrhage was evaluated using glycophorin A staining, and intraplaque neovessels were evaluated using CD34 (Cluster of differentiation) stain as an endothelial cell marker or NG2 (Neuron-glial antigen 2) and CD146 stains as pericyte markers. Additionally, the relationships between the TOF-MRA findings and the carotid plaque pathologies were evaluated. (3) Results: Of the 49 stenoses, 28 had high-intensity signals (TOF-HIS group) and 21 had iso-intensity signals (TOF-IIS group) on TOF-MRA. The density of the CD34-positive neovessels was equivalent in both groups. However, the NG2- and CD146-positive neovessels had significantly higher densities in the TOF-HIS group than in the TOF-IIS group. (4) Conclusion: The presence of a high-intensity signal on TOF-MRA in carotid plaques was associated with intraplaque hemorrhage and few pericytes in intraplaque neovessels. These findings may contribute to the development of new therapeutic strategies focusing on pericytes.

Highlights

An unstable carotid plaque can cause thromboembolic stroke [1,2]
We have focused on pericytes of intraplaque neovessels and reported that pericytes may be involved in carotid plaque hemorrhage based on evaluations of plaque from patients who underwent carotid endarterectomy (CEA) [7]
A histopathological study using anti-NG2 and CD146 antibodies as pericyte markers showed that pericytes in carotid plaque were associated with asymptomatic carotid stenosis [8]

Summary

Introduction

An unstable carotid plaque can cause thromboembolic stroke [1,2]. Unstable carotid plaques are defined as plaques with intraplaque hemorrhage (IPH), an incomplete fibrous cap, and a large lipid-rich necrotic core [3]. We have focused on pericytes of intraplaque neovessels and reported that pericytes may be involved in carotid plaque hemorrhage based on evaluations of plaque from patients who underwent carotid endarterectomy (CEA) [7]. The pericytes may play a role in stabilizing plaques in the carotid artery [8]. IPH has been reported as the principal factor for progression to unstable plaque and can be confirmed on magnetic resonance imaging (MRI) of human carotid plaques [10]. An association between high-intensity carotid plaque on time-of-flight (TOF) magnetic resonance angiography (MRA) and IPH has been reported [11]. The present study aims to elucidate the associations between the pericytes in intraplaque neovessels and the MRA findings

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Methods

Results

Discussion

Conclusion