Z. Mallat et al., Expression of interleukin-10 in advanced human atherosclerotic plaques - Relation to inducible nitric oxide synthase expression and cell death, ART THROM V, 19(3), 1999, pp. 611-616
Inflammation is a major feature of human atherosclerosis and is central to
development and progression of the disease. A variety of proinflammatory cy
tokines are expressed in the atherosclerotic plaque and may modulate extrac
ellular matrix remodeling, cell proliferation, and cell death. Little is kn
own, however, about the expression and potential role of anti-inflammatory
cytokines in human atherosclerosis. Interleukin-10 (IL-10) is a major antii
nflammatory cytokine whose expression and potential effects in advanced hum
an atherosclerotic plaques have not been evaluated. We studied 21 advanced
human atherosclerotic plaques. IL-10 expression was analyzed by use of reve
rse transcription-polymerase chain reaction and immunohistochemical techniq
ues. Inducible nitric oxide synthase expression was assessed by using immun
ohistochemistry, and cell death was determined by use of the TUNEL method.
Reverse transcription-polymerase chain reaction identified IL-10 mRNA in 12
of 17 atherosclerotic plaques. Immunohistochemical staining of serial sect
ions and double staining identified immunoreactive IL-10 mainly in macropha
ges, as well as in smooth muscle cells. Consistent with its anti-inflammato
ry properties, high levels of IL-10 expression were associated with signifi
cant decrease in inducible nitric oxide synthase expression (P<0.0001) and
cell death (P<0.0001). Hence, IL-10, a potent anti-inflammatory cytokine, i
s expressed in a substantial number of advanced human atherosclerotic plaqu
es and might contribute to the modulation of the local inflammatory respons
e and protect from excessive cell death in the plaque.