Two-photon microscopy on vital carotid arteries: imaging the relationship between collagen and inflammatory cells in atherosclerotic plaques

• Published in: Journal of Biomedical Optics 2008-07, Vol.13 (4), p.044022-0440210
• Main Authors: Megens, Remco T. A, oude Egbrink, Mirjam G. A, Merkx, Maarten, Slaaf, Dick W, van Zandvoort, Marc A. M. J
• Format: Article
• Language: English
• Subjects: Age; Animals; Arteritis - pathology; atherogenesis; Carotid arteries; Carotid Arteries - pathology; Carotid Artery Diseases - pathology; collagen; Collagen - ultrastructure; Collagens; Density; Diets; Endothelium; inflammatory cells; Marking; Mice; Mice, Inbred C57BL; Microscopy, Fluorescence, Multiphoton - methods; Progressions; two-photon microscopy
• ISSN: 1083-3668; 1560-2281
• DOI: 10.1117/1.2965542

We used two-photon laser scanning microscopy (TPLSM) to demonstrate for the first time its potential in studying relational details at the cellular level of atherogenesis in intact, viable mouse carotid arteries. Isolated and mounted arteries of ApoE-/-mice, aged 15 or (7 and on western diet), were imaged after labeling with specific fluorescent markers for cell nuclei, inflammatory cells, collagen, and lipids. Data were compared with C57BL6/J mice fed a chow diet. Control vessels had intact endothelium without adhering blood cells or significant intimal collagen labeling. In ApoE-/-mice already at , inflammatory cells adhered to the endothelium and increased labeling of collagen was observed in tunica intima at both lesion-prone and non-lesion-prone sites, indicating endothelium activation. In plaques, internalized inflammatory cell density increased with age and plaque progression in tunicae adventitia and intima, but not media. In the whole plaque, aging or plaque progression did not alter the direct relationship between inflammatory cells and collagen. However, within the fibrous caps specifically, direct contact between inflammatory cells and collagen increased with age. This study demonstrates the potential of TPLSM in determining detailed information regarding the complex relationship between inflammatory cells and collagen during atherogenesis.