A. Lopezcandales et al., EFFECTS OF ULTRAVIOLET-LIGHT IN VASCULAR CELLS IN-VITRO AND IN INTACTATHEROSCLEROTIC EXPLANTS - POTENTIAL ROLE OF APOPTOSIS IN VASCULAR BIOLOGY, Biochemistry and cell biology, 74(3), 1996, pp. 333-345
Complex cell-to-cell interactions are known to participate during vasc
ular injury and remodeling, resulting in smooth muscle cell proliferat
ion. Mechanical interventions have yielded little benefit in limiting
this process and several site-specific genetic therapies are not yet c
linically available. The aim of this study was to delineate the effect
of very short wavelength ultraviolet (UVC) light therapy on the viabi
lity of macrophage and smooth muscle cells. Vascular cells were both t
reated in vitro and in intact explanted atherosclerotic aortic segment
s ex vivo with WC light. Brief exposure to short wavelength WC light i
n the absence of photosensitizers elicited a differential temporal and
functional response among treated cells. However, dramatic reduction
in both cellular viability and proliferative capacity with eventual ce
ll demise was observed in all WC-treated cells. Flow cytometry and imm
unohistochemical analyses revealed the presence of extensive DNA fragm
entation, suggestive of apoptosis as a predominant pathway of cell dea
th in these cells exposed to UVC light. We hypothesize that selective
induction of apoptosis, in contrast to necrosis, with WC light may rep
resent a beneficial approach to interdict the complex biologic cascade
of messengers that participate in the restenotic response to vascular
injury.