Mc. Vozenin-brotons et al., Histopathological and cellular studies of a case of cutaneous radiation syndrome after accidental chronic exposure to a cesium source, RADIAT RES, 152(3), 1999, pp. 332-337
This study was designed for the histopathological, cellular and biochemical
characterization of a skin lesion removed surgically from a young male sev
eral months after accidental exposure to cesium-137, with an emphasis on ex
pression of transforming growth factor beta 1 (TGFB1) and tumor necrosis fa
ctor alpha (TNFA) and the occurrence of apoptosis. Under a hypertrophic epi
dermis, a highly inhomogeneous inflammatory dermis was observed, together w
ith fibroblastic proliferation in necrotic areas. Immunostaining revealed o
verexpression of TGFB1 and TNFA inside the keratinocytes of the hypertrophi
c epidermis as wed as in the cytoplasm of the fibroblasts and connective ti
ssue of the mixed fibrotic and necrotic dermis. Inside this dermis, the TUN
EL assay revealed areas containing numerous apoptotic fibroblasts next to a
reas of normal viable cells. Overexpression of TGFB1 was found in the condi
tioned medium and cellular fractions of both hypertrophic keratinocytes and
fibrotic fibroblasts. This overexpression lasted for at least three passag
es in tissue culture. The present observations were consistent with the cen
tral role of TGFB1 in the determination of chronic radiation-induced damage
to the skin and a significant involvement of TNFA. In addition, programmed
cell death appeared to take place during the remodeling of the mixed fibro
tic and necrotic tissue. (C) 1999 by Radiation Research Society.