Age-related and dexamethasone-induced changes in cathepsins E and D in rat thymic and splenic cells.
Age-related and dexamethasone-induced changes in cathepsins E and D in rat thymic and splenic cells.
复制标题
大鼠胸腺和脾细胞组织蛋白酶 E 和 D 与年龄相关和地塞米松诱导的变化。
DOI：
10.1006/abbi.1996.0401
复制
发表时间：
1996
影响因子：
3.9
通讯作者：
K. Yamamoto
中科院分区：
文献类型：
--
作者：
K. Nishishita;H. Sakai;E. Sakai;Y. Kato;K. Yamamoto
用免疫组织化学和定量分析方法研究了地塞米松（DEX）和地塞米松（DEX）对大鼠胸腺和脾脏中两种不同的细胞内天冬氨酸蛋白酶组织蛋白酶E（CE）和组织蛋白酶D（CD）的细胞水平、分布和分子形式的影响。在胸腺中，CE主要局限于胸腺细胞和巨噬细胞样细胞，而CD主要与基质细胞。在8周龄以下的年轻大鼠中观察到的胸腺CE水平升高在老年大鼠（78-80周龄）中显著降低，这与胸腺的退化一致，而年轻大鼠和老年大鼠之间的胸腺CD水平几乎没有差异。DEX皮下给药也引起胸腺CE水平显着下降，以响应胸腺细胞的耗竭。DEX处理后，胸腺基质细胞内CD大量积聚.免疫印迹分析表明，CE在从年轻大鼠分离的胸腺细胞主要由一个46 kDa的proform大大转化成一个42 kDa的成熟形式在DEX处理的胸腺细胞。然而，在正常老化过程中几乎没有观察到这种转化。在脾脏中，巨噬细胞样细胞和淋巴细胞中也富含CE，且其水平在青年和老年大鼠之间无显著变化。然而，DEX治疗导致脾脏CE和CD水平显著降低，与白色髓的消耗一致。在检查的淋巴细胞类型中，脾B细胞在CE中最丰富。胸腺细胞和脾T细胞中的CE水平是循环淋巴细胞中CE水平的两倍以上。我们得出结论，CE是与活化诱导的淋巴细胞耗竭的过程。
Age-related and dexamethasone (DEX)-induced changes in the cellular levels, distributions, and molecular forms of two distinct intracellular aspartic proteinases, cathepsin E (CE) and cathepsin D (CD), were investigated in rat thymus and spleen by immunohistochemical and quantitative analyses. In the thymus, CE was predominantly restricted to thymocytes and macrophage-like cells, whereas CD was associated mainly with the stromal cells. The increased thymic CE level observed in young rats up to 8 weeks of age was markedly decreased in aged rats (78-80 weeks of age), in accordance with the involution of the thymus, while there was little difference in the thymic CD level between young and aged rats. Subcutaneous administration of DEX also caused a marked decrease of the thymic CE level in response to the depletion of thymocytes. In contrast, a great accumulation of CD occurred in the thymic stromal cells after DEX treatment. Immunoblotting analyses revealed that CE in thymocytes isolated from young rats consisted predominantly of a 46-kDa proform which was greatly converted into a 42-kDa mature form in DEX-treated thymocytes. This conversion, however, was scarcely observed during the normal aging process. In the spleen, CE was also abundant in macrophage-like cells and lymphocytes and its level was not significantly changed between young and aged rats. However, DEX treatment caused a marked decrease of the splenic CE and CD levels in accordance with the depletion of the white pulp. Among the lymphoid cell types examined, splenic B cells were the most abundant in CE. The CE level in thymocytes and splenic T-cells was more than twice that in circulating lymphocytes. We concluded that CE is related to the process of activation-induced lymphocyte depletion.