High-resolution optical mapping of inflammatory macrophages following endovascular arterial injury.

Abstract

PURPOSE:

Inflammation following arterial injury mediates vascular restenosis, a leading cause of cardiovascular morbidity. Here we utilize intravital microscopy (IVM) and a dextran-coated nanosensor to spatially map inflammatory macrophages in vivo following endovascular injury of murine carotid arteries.

PROCEDURES:

C57Bl/6 mice (n = 23) underwent endovascular guidewire carotid arterial injury. At day 14 or day 28 post-injury, mice underwent fluorescence IVM, 24 h after injection with the near-infrared fluorescent macrophage nanosensor CLIO-VT680. Adventitial collagen was concomitantly imaged using second harmonic generation (SHG) IVM. Correlative fluorescence microscopy and immunohistochemistry were performed.

RESULTS:

Two-plane IVM reconstructions detected macrophage inflammation in the arterial wall that was elevated at day 14 compared to day 28 animals (P < 0.05). SHG-based collagen imaging of the outer arterial wall facilitated analysis of the macrophage-rich, inflamed neointima. Histological analyses and fluorescence microscopy data demonstrated increased macrophage infiltration in day 14 compared to day 28 neointima.

CONCLUSIONS:

We demonstrate that the macrophage response to arterial injury can be imaged in vivo using IVM-based molecular imaging, and shows a higher macrophage influx at day 14 compared to day 28 post-injury.

• Authors: Amit Saxena, Chase W Kessinger, Brian Thompson, Jason R McCarthy, Yoshiko Iwamoto, Charles P Lin, Farouc A Jaffer
• Journal: Molecular imaging and biology (Mol Imaging Biol) Vol. 15 Issue 3 Pg. 282-9 (Jun 2013) ISSN: 1860-2002 [Electronic] United States
• PMID: 23090852 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Topics

• Animals
• Carotid Arteries (pathology)
• Carotid Artery Injuries (diagnosis)
• Cell Proliferation
• Endothelial Cells (pathology)
• Endothelium, Vascular (pathology)
• Image Processing, Computer-Assisted
• Inflammation (pathology)
• Macrophages (pathology)
• Mice
• Mice, Inbred C57BL
• Microscopy, Fluorescence
• Neointima (pathology)
• Optical Imaging (methods)
• Vascular System Injuries (diagnosis, pathology)