Résumé
We studied the expression of caveolin-1 in the spinal cords of rats using 60Co gamma-ray irradiation (single dose of 8 Gray (Gy)) in order to determine the possible involvement of caveolin-1 in the tissues of the central nervous system after irradiation. Spinal cords sampled at days 1, 4, and 9 post-irradiation (PI) (n = 5 per each time point) were analyzed by Western blot and immunohistochemistry. Western blot analysis showed that the expression of caveolin-1 was significantly increased at day 1 PI (p < 0.05), and returned to the level of normal control rats on days 4 and 9 PI. Immunohistochemistry showed that caveolin-1 immunoreactivity was enhanced in some glial cells, vascular endothelial cells, and neurons in the spinal cords. The increased expression of glial fibrillary acidic protein (GFAP), a marker for an astroglial reaction, was consistent with that of caveolin-1. In addition, caveolin-1 was co-localized in hypertrophied GFAP-positive astrocytes. Taking all these facts into consideration, we postulate that irradiation induces the increased expression of caveolin-1 in cells of the central nervous system, and that its increased expression in astrocytes may contribute to hypertrophy of astrocytes in the spinal cord after irradiation. The precise role of caveolin-1 in the spinal cords should be studied further.
Sujets)
Animaux , Mâle , Rats , Astrocytes/métabolisme , Technique de Western , Cavéoline-1/biosynthèse , Rayons gamma , Protéine gliofibrillaire acide/biosynthèse , Immunohistochimie , Rat Sprague-Dawley , Moelle spinale/cytologie , Irradiation corporelle totaleRésumé
The expression of caveolin-1 and -2 in the retina was examined; Western blot analysis showed that both were present. Immunohistochemistry indicated that caveolin-1 was expressed in the majority of retinal layers, including the ganglion cell layer, inner plexiform layer, outer plexiform layer, and in the vascular endothelial cells of the retina. Caveolin-2 was primarily immunostained in the vessels, but in a few other elements as well. This is the first demonstration of caveolin differential expression in the retina of rats, and suggests that caveolin plays an important role in signal transduction in glial cells and neuronal cells.