Phenotypic modulation of intima and media smooth muscle cells in fatal cases of coronary artery lesion.
OBJECTIVE
Characterize the phenotypic features of media and intima coronary artery smooth muscle cells (SMCs) in mildly stenotic plaques, erosions, stable plaques, and in-stent restenosis.


RESULTS
Expression of alpha-smooth muscle actin (alpha-SMA), smooth muscle myosin heavy chains (SMMHCs), and smoothelin was investigated by immunohistochemistry followed by morphometric quantification. The cross-sectional area and the expression of cytoskeletal proteins in the media were lower in restenotic lesions and, to a lesser extent, in stable plaques compared with mildly stenotic plaques and erosions. An important expression of alpha-SMA was detected in the intima of the different lesions; moreover, alpha-SMA staining was significantly larger in erosions compared with all other conditions. In the same location, a striking decrease of SMMHCs and a disappearance of smoothelin were observed in all situations.


CONCLUSIONS
Medial atrophy is prevalent in restenotic lesions and stable plaques compared with mildly stenotic plaques and erosions. Intimal SMCs of all situations exhibit a phenotypic profile, suggesting that they have modulated into myofibroblasts (MFs). The high accumulation of alpha-SMA-positive MFs in erosions compared with stable plaques correlates with the higher appearance of thrombotic complications in this situation.
Hao
Hiroyuki
H
Department of Pathology and Immunology, University of Geneva-CMU, Geneva, Switzerland.
Gabbiani
Giulio
G
Camenzind
Edoardo
E
Bacchetta
Marc
M
Virmani
Renu
R
Bochaton-Piallat
Marie-Luce
ML
D000199:Actins / Q000378:metabolism; D015703:Antigens, CD / Q000378:metabolism; D018952:Antigens, CD34 / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D001284:Atrophy; D003324:Coronary Artery Disease / Q000378:metabolism* / Q000401:mortality / Q000473:pathology*; D023921:Coronary Stenosis / Q000378:metabolism / Q000401:mortality / Q000473:pathology; D003331:Coronary Vessels / Q000378:metabolism* / Q000473:pathology*; D003598:Cytoskeletal Proteins / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D009124:Muscle Proteins / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000378:metabolism* / Q000473:pathology*; D018995:Myosin Heavy Chains / Q000378:metabolism; D010641:Phenotype; D024745:Smooth Muscle Myosins / Q000378:metabolism; D017539:Tunica Intima / Q000378:metabolism / Q000473:pathology; D017540:Tunica Media / Q000378:metabolism / Q000473:pathology; D000097382:CD68 Molecule
D000199:Actins; D015703:Antigens, CD; D018952:Antigens, CD34; D015214:Antigens, Differentiation, Myelomonocytic; D003598:Cytoskeletal Proteins; D009124:Muscle Proteins; D018995:Myosin Heavy Chains; D024745:Smooth Muscle Myosins; C067980:CD68 antigen, human; D000097382:CD68 Molecule; C100762:SMTN protein, human