Enhanced expression of adipocyte-type fatty acid binding protein in murine lymphocytes in response to dexamethasone treatment
Enhanced expression of adipocyte-type fatty acid binding protein in murine lymphocytes in response to dexamethasone treatment
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DOI：
10.1007/s11010-005-9050-1
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发表时间：
2007-05-01
影响因子：
4.3
通讯作者：
Kondo, Hisatake
中科院分区：
文献类型：
--
作者：
Abdelwahab, Soha Abdelkawi;Owada, Yuji;Kondo, Hisatake
脂肪酸对淋巴细胞凋亡过程有很大影响，淋巴细胞凋亡被认为是人类和动物免疫反应的调节因素。然而，脂肪酸在淋巴细胞凋亡过程中的作用机制尚不完全清楚。在这项研究中，我们表明，在体内和培养的淋巴细胞中给予地塞米松（DEX）后，脂肪细胞型脂肪酸结合蛋白（A-FABP）的出现被诱导，并且其独特的核定位与DEX诱导的细胞凋亡过程密切相关。在小鼠脾脏的免疫组织化学中，DEX刺激后3小时开始出现A-FABP免疫反应性，并在治疗后8小时大量定位于细胞核，而在正常以及注射后24小时脾脏的淋巴细胞中未观察到A-FABP免疫反应性。在小鼠 T 细胞白血病 CTLL-2 细胞中，当 IL-2 修复和 DEX 处理一起诱导细胞凋亡时，A-FABP 免疫反应性也在细胞质和细胞核中被诱导，而在 IL-2 存在的情况下，A-FABP 免疫反应性被限制在 DEX 处理的细胞质中。另一方面，仅通过 IL-2 修复无法检测到 A-FABP 免疫反应性。目前的研究结果表明，A-FABP 及其配体脂肪酸在 DEX 诱导的细胞凋亡和免疫调节过程中发挥着重要作用。
Fatty acids have a great influence on the process of lymphocyte apoptosis which is considered as a modulating factor of immune response in both humans and animals. However the mechanism underlying the function of fatty acids in the process of lymphocyte apoptosis is not fully understood. In this study we show that the appearance of adipocyte-type fatty acid binding protein (A-FABP) is induced upon administration of dexamethasone (DEX) in both in vivo and cultured lymphocytes, and its distinct nuclear localization occurs in close relation to the DEX-induced apoptosis process. In immuunohistochemistry of mouse spleen, A-FABP-immunoreactivity starts to occur 3 h after DEX stimulation, and it massively localizes in the nucleus 8 h after the treatment, while no A-FABP-immunoreactivity is discerned in the lymphocytes of normal as well as 24 h post-injection spleen. In the murine T-cell leukemia CTLL-2 cells, A-FABP-immunoreactivity is also induced in both of the cytoplasm and nucleus when the apoptosis is induced by IL-2 retrieval together with DEX treatment, while in the presence of IL-2 A-FABP-immunoreactivity is confined to the cytoplasm with DEX trreatment. On the other hand, A-FABP-immunoreactivity is not detected by IL-2 retrieval alone. The present findings altogether suggest that A-FABP and its ligands, fatty acids, play an important role in the process of apoptosis and the immune modulation induced by DEX.