Morphological and immunohistochemical changes to thymic epithelial cells in the irradiated and recovering rat thymus
Morphological and immunohistochemical changes to thymic epithelial cells in the irradiated and recovering rat thymus
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DOI：
10.1679/aohc.67.149
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发表时间：
2004-06-01
影响因子：
--
通讯作者：
Fukumoto, T
中科院分区：
文献类型：
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作者：
Irifune, T;Tamechika, M;Fukumoto, T
本研究分析了大鼠胸腺照射和恢复过程中胸腺上皮细胞的形态和免疫组织化学变化。观察发现，胸腺细胞数量在照射后最初严重减少，但在6Gy3~5d和8Gy7~11d突然增加。为了分析照射后胸腺细胞突然恢复的机制，用免疫组织化学方法研究了p63在正常胸腺和照射后胸腺中的表达，该抗原的表达可能与胸腺上皮细胞的增殖有关。在胎儿胸腺组织中，胸腺上皮细胞是p63强阳性的主要细胞类型。P63在正常成人胸腺组织中也有散在表达，尤其是在被膜下区域。照射后胸腺中p63阳性细胞数量增加，提示胸腺上皮细胞可能正在发生修复或更新，因为p63对瞬时放大的胸腺上皮细胞更具特异性。对照射和再生胸腺组织中p63表达的RT-PCR分析也表明，与正常胸腺相比，照射后p63的表达增加。这些结果表明，胸腺微环境的变化，特别是与胸腺上皮细胞的修复和更新有关的变化，可能对正常胸腺以及照射和恢复的胸腺的胸腺细胞增殖有重要影响。
The present study analyzed morphological and immunohistochemical changes of thymic epithelial cells in the irradiated and recovering rat thymus. Observations showed the number of thymocytes was initially severely reduced after irradiation but abruptly increased on days 3 to 5 after 6 Gy and on days 7 to 11 after 8 Gy irradiation. To analyse the mechanisms for this abrupt recovery of the thymocytes after irradiation, the expression of p63 in the normal and irradiated thymus was immunohistochemically studied as the expression of this antigen may be related to the proliferation of epithelial cells. In the fetal thymus tissue, thymic epithelial cells were the principal cell type that stained strongly positive for p63. The sporadic expression of p63 was also observed in the normal adult thymus tissue, especially in the subcapsular region. An increased number of p63- positive cells in the thymus after irradiation indicates that repair or renewal of the thymic epithelial cells may be taking place because p63 is more specific to transient amplifying thymic epithelial cells. A RT-PCR analysis of p63 expression in irradiated and regenerating thymus tissue also showed an increased expression of p63 after irradiation compared with that of the normal thymus. These results suggest that changes in the thymic microenvironment-especially in relation to the repair and renewal of thymic epithelial cells-may have an important influence on thymocyte proliferation in the normal thymus as well as in the irradiated and recovering thymus.