Characterization of FAP-1 expression and function in thyroid follicular cells
Characterization of FAP-1 expression and function in thyroid follicular cells
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DOI：
10.1210/en.140.11.5431
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发表时间：
1999-11-01
期刊：
影响因子：
4.8
通讯作者：
Baker, JR
中科院分区：
文献类型：
--
作者：
Myc, A;Arscott, PL;Baker, JR
人甲状腺细胞对Fas介导的程序性细胞死亡（PCD）具有抗性。有报道称，一种不稳定的蛋白抑制剂参与了甲状腺细胞的PCD保护作用，其作用可通过在用激动剂抗Fas Ab处理甲状腺细胞的同时用放线菌酮（CHX）孵育来逆转。Fas相关磷酸酶-1（FAP-1）是一种与Fas负调控结构域相互作用的蛋白质，在FAP-1转染的Jurkat细胞中阻断Fas介导的凋亡。我们研究了FAP-1可能参与保护人类甲状腺细胞免受Fas介导的PCD的可能性。用核糖核酸酶保护试验检测原代甲状腺细胞中FAP-Ⅰ mRNA。使用多克隆抗FAP-1 Ab通过免疫组织化学染色和流式细胞术确认FAP-1蛋白的存在。FAP-1蛋白也从甲状腺细胞中消失。为了确定FAP-1是否是甲状腺细胞中PCD的功能性抑制剂，我们将甲状腺细胞与合成SLV（Ac-SLV）三肽一起孵育，以与Fas竞争与FAP-1的相互作用。与用对照三肽处理的细胞相比，用Ac-SLV三肽处理的甲状腺细胞显示出显著增加的细胞死亡。此外，在次优浓度的CHX的存在下，与用对照三肽处理的甲状腺细胞相比，Ac-SLV三肽产生了Fas介导的PCD的强烈的协同增加。这些结果暗示FAP-1作为Fas诱导的甲状腺细胞PCD的调节剂。
Human thyrocytes are resistant to Fas-mediated programmed cell death (PCD). It has been reported that a labile protein inhibitor is involved in the protection of thyrocytes from PCD, and its action can be reversed by incubation of thyrocytes with cycloheximide (CHX) during treatment with agonist anti-Fas Ab. Fas-associated phosphatase-l (FAP-1) is a protein that has been shown to interact with the negative regulatory domain of Fas and block Fas-mediated apoptosis in FAP-I transfected Jurkat cells. We investigated the possibility that FAP-1 might be involved in protection against Fas-mediated PCD in human thyrocytes. FAP-I mRNA was detected in primary thyrocytes using a ribonuclease protection assay. The presence of FAP-1 protein was confirmed by immunohistochemical staining and flow cytometry using a polyclonal anti-FAP-l Ab. FAP-1 protein also disappeared from thyroid cells in response to CHX. To determine whether FAP-1 is a functional inhibitor of PCD in thyrocytes, we incubated thyrocytes with synthetic SLV (Ac-SLV) tripeptide to compete with Fas for interaction with FAP-I. Thyrocytes treated with Ac-SLV tripeptide showed significantly increased cell death as compared to cells treated with control tripeptide. In addition, in the presence of a suboptimal concentration of CHX, the Ac-SLV tripeptide yielded a strong, synergistic increase in Fas-mediated PCD as compared to thyrocytes treated with control tripeptide. These results implicate FAP-1 as a regulator of Fas-induced PCD in thyrocytes.