Presence of alpha-smooth muscle actin-positive endothelial cells in the luminal surface of adult aorta.
Alpha-smooth muscle actin-positive endothelial cells have not been found in adult aortic endothelium except valve leaflets. Here, using en face immunostaining method, we identified alpha-smooth muscle actin-positive endothelial cells in the luminal surface of rat, mouse and human thoracic aortas. These cells express both endothelial markers and definite smooth muscle cell markers and were only occasionally observed in thoracic aorta of wild type mice and rats. Their density did not increase with aging. Given that alpha-smooth muscle actin-positive endothelial cells express low level of vascular endothelial-cadherin that is important for the maintenance of cell contact, these cells were frequently detected in the thoracic aorta of 5-week-old apolipoprotein-E deficient mice. In 20- to 24-week-old apolipoprotein-E deficient mice, marked accumulation of alpha-smooth muscle actin-positive endothelial cells was observed especially in the luminal surface of atheromatous plaques. Our findings indicate the existence of alpha-smooth muscle actin-positive endothelial cells in adult aortic endothelium and the possible association with progression of atherosclerosis.
Azuma
Kosuke
K
Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
Ichimura
Kouichiro
K
Mita
Tomoya
T
Nakayama
Shiho
S
Jin
Wen Long
WL
Hirose
Takahisa
T
Fujitani
Yoshio
Y
Sumiyoshi
Katsuhiko
K
Shimada
Kazunori
K
Daida
Hiroyuki
H
Sakai
Tatsuo
T
Mitsumata
Masako
M
Kawamori
Ryuzo
R
Watada
Hirotaka
H
D000199:Actins / Q000032:analysis / Q000378:metabolism*; D000375:Aging / Q000378:metabolism; D000818:Animals; D001013:Aorta, Thoracic / Q000378:metabolism*; D001057:Apolipoproteins E / Q000235:genetics; D050197:Atherosclerosis / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008817:Mice, Mutant Strains; D051381:Rats
D000199:Actins; D001057:Apolipoproteins E; C541116:ACTA2 protein, human; C558396:Acta2 protein, mouse; C498862:Acta2 protein, rat