P. Zaugg et al., Sorting of murine vascular smooth muscle cells during wound healing in thechicken chorioallantoic membrane, EXP CELL RE, 253(2), 1999, pp. 599-606
The vascular wall is built up of a heterogeneous population of smooth muscl
e cells, which exhibit not only morphological distinctions but also importa
nt differences in the composition of their structural and contractile prote
ins. "Epithelioid" smooth muscle cells correspond to an intimal-like type a
nd display features associated with immaturity, whereas "spindle-shaped" ce
lls closely resemble the more typical medial smooth muscle population. We h
ave investigated the integration of these two cell types into the vascular
architecture of an in vivo wound-healing model. Stably transfected with the
beta-galactosidase gene, intima- and media-like cells were injected intrav
enously into the chicken chorioallantoic membrane, within which superficial
foci of granulation tissue had been created by thermal or chemical injury.
At 24 to 72 h after injection, cells had homed in on the lesion sites and
were observed in juxtaposition to the endothelial lining of the capillaries
. They began to deposit laminin, thereby indicating an impending role in th
e formation of the vascular wall. Intima- and media-like smooth muscle cell
s did not differ in their capacity to associate with capillaries, and, in s
o doing, their biochemical lineage characteristics became indistinguishable
from one another. However, intima-like cells also penetrated the adventiti
al and medial layers of arteries. These findings reveal vascular smooth mus
cle cells to possess an extraordinary degree of plasticity, being able to a
dapt flexibly to changes in functional demands. (C) 1999 Academic Press.