Association between Pericytes in Intraplaque Neovessels and Magnetic Resonance Angiography Findings

Area of Science:

• Vascular Biology
• Neurology
• Radiology

Background:

• Pericytes contribute to neovascularization in advanced atherosclerotic lesions.
• The specific role of pericytes in human carotid plaques remains largely unknown.
• High-intensity signals on Time-of-Flight Magnetic Resonance Angiography (TOF-MRA) in carotid plaques correlate with instability and ischemic stroke risk.

Purpose of the Study:

• To investigate the association between pericytes within intraplaque neovessels and TOF-MRA findings in human carotid plaques.
• To explore the relationship between carotid plaque characteristics, including intraplaque hemorrhage and neovascularization, and TOF-MRA signal intensity.

Main Methods:

• Retrospective analysis of 49 carotid plaques from patients who underwent carotid endarterectomy.
• Histopathological evaluation using Glycophorin A for intraplaque hemorrhage.
• Immunohistochemical staining for CD34 (endothelial cells), NG2, and CD146 (pericytes) to assess neovessel density.
• Correlation of plaque pathologies with TOF-MRA signal intensity (high-intensity vs. iso-intensity signals).

Main Results:

• Carotid plaques with high-intensity signals on TOF-MRA (TOF-HIS group, n=28) showed significantly higher densities of NG2- and CD146-positive pericytes compared to plaques with iso-intensity signals (TOF-IIS group, n=21).
• The density of CD34-positive neovessels was comparable between the TOF-HIS and TOF-IIS groups.
• High-intensity signals on TOF-MRA were associated with intraplaque hemorrhage.

Conclusions:

• A high-intensity signal on TOF-MRA in carotid plaques is linked to intraplaque hemorrhage and a reduced pericyte presence in intraplaque neovessels.
• These findings suggest that TOF-MRA can provide insights into carotid plaque composition and stability.
• The study may inform the development of novel therapeutic strategies targeting pericytes for atherosclerotic disease.