Regulation of cholecystokinin-mediated amylase secretion by leptin in rat pancreatic acinar tumor cell line AR42J
Regulation of cholecystokinin-mediated amylase secretion by leptin in rat pancreatic acinar tumor cell line AR42J
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DOI：
10.1097/00006676-199910000-00002
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发表时间：
1999-10-01
期刊：
影响因子：
2.9
通讯作者：
Wu, SV
中科院分区：
文献类型：
--
作者：
Harris, DM;Flannigan, KL;Wu, SV
瘦素受体的长型（被认为具有完全信号传导能力的同种型）的表达已在中枢神经系统和几种外周细胞类型中报道。然而，只有少数细胞系已被证明表达受体的长形式。AR 42 J是一种来源于阿扎丝氨酸处理的大鼠胰腺的细胞系，是胰腺腺泡细胞分泌的常见模型。在这项研究中，瘦素受体变异体和瘦素行动的存在进行了评估，在这个细胞系。通过逆转录-聚合酶链反应（RT-PCR）在AR 42 J细胞中检测瘦素受体的长和短形式的信使RNA，并通过DNA测序证实受体的真实性。竞争结合研究表明，放射性标记的瘦素与胆囊收缩素（CCK）的结合是特异性的，且不发生交叉反应。在存在和不存在CCK（一种已知的胰腺促分泌剂）的情况下，进一步评估瘦素对淀粉酶释放和细胞内钙动员的生物学效应。虽然单独的瘦素（小于或等于200 ng/ml）不影响基础淀粉酶的释放，它抑制淀粉酶释放刺激1 nM CCK的48%。单独的瘦素对钙动员没有显著影响。而10和100 ng/ml的leptin预处理可增强CCK刺激的钙反应。这些数据表明，大鼠胰腺肿瘤细胞系AR 42 J表达瘦素受体的功能形式，调节CCK的钙动员和淀粉酶释放的作用。
Expression of the long form of the leptin receptor,the isoform that is considered to have full signaling capability, has been reported in the central nervous system and several peripheral cell types. However, only a few cell lines have been shown to express the long form of the receptor. AR42J, a cell line derived from azaserine-treated rat pancreas, is a common model for pancreatic acinar cell secretion. In this study, the presence of leptin-receptor variants and leptin action was evaluated in this cell line. Messenger RNAs for both the long and a short form of the leptin receptor were detected by reverse transcription-polymerase chain reaction (RT-PCR) in AR42J cells, and authenticity of the receptor was confirmed by DNA sequencing. Competitive binding studies demonstrated that binding of radiolabeled leptin was specific and did not cross- react with cholecystokinin (CCK). Biologic effects of leptin on amylase release and intracellular calcium mobilization were further assessed in the presence and the absence of CCK, a known pancreatic secretogogue. Although leptin alone (less than or equal to 200 ng/ml) did not affect basal amylase release, it inhibited amylase release stimulated by 1 nM CCK by 48%. Leptin alone had no significant effect on calcium mobilization. However, pretreat ment of leptin (10 and 100 ng/ml) enhanced calcium responses stimulated by CCK. These data demonstrate that the rat pancreatic tumor cell line AR42J expresses a functional form of the leptin receptor that modulates the action of CCK in calcium mobilization and amylase release.