Expression of TNF-alpha and TGF-beta 1 in the rat brain after a single high-dose irradiation.
Cytokines and growth factors are important regulatory proteins controlling the growth and differentiation of normal and malignant glial cells. In this study, we investigated the expression and origin of tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta 1 (TGF-beta 1) in the subacute brain injury after a single high-dose irradiation using 60 Sprague-Dawley rats. The right cerebral hemispheres of rats were exposed to a single 10 Gy dose of gamma rays using Ir-192. The radiation effect was assessed at 1 week, 2 weeks, 4 weeks, 6 weeks, and 8 weeks after irradiation, and the results were compared with those in sham operation group. Histological changes characteristic of radiation injury were correlated with the duration after the single dose irradiation. The loss of cortical thickness also increased with the lapse of time after irradiation. The TNF-alpha expression in the irradiated cerebral hemispheres was significantly increased compared with that in the sham operation group. TGF-beta 1 expression was also increased in the irradiated hemispheres. Immunohistochemical study revealed that TGF-beta 1 was expressed predominantly by infiltrating macrophages and astrocytes around the necrotic areas. These findings indicate that TNF-alpha and TGF-beta 1 may play prominent roles in the radiation injuries after a single high-dose irradiation.
Kim
Se-Hoon
SH
Department of Neurosurgery, Medical College, Korea University, Seoul, Korea.
Lim
Dong-Jun
DJ
Chung
Yong-Gu
YG
Cho
Tai-Hyoung
TH
Lim
Seong-Jun
SJ
Kim
Woo-Jae
WJ
Suh
Jung-Keun
JK
D000818:Animals; D001921:Brain / Q000276:immunology / Q000473:pathology / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D007150:Immunohistochemistry / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000096:biosynthesis*; D053773:Transforming Growth Factor beta1; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
C508962:Tgfb1 protein, rat; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D014409:Tumor Necrosis Factor-alpha