Pancreatic Reg I Binds MKP-1 and Regulates Cyclin D in Pancreatic-Derived Cells
Pancreatic Reg I Binds MKP-1 and Regulates Cyclin D in Pancreatic-Derived Cells
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DOI：
10.1016/j.jss.2008.03.047
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发表时间：
2008-11-01
影响因子：
2.2
通讯作者：
Zenilman, Michael E.
中科院分区：
文献类型：
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作者：
Mueller, Cathy M.;Zhang, Hong;Zenilman, Michael E.
背景胰腺再生（reg I）基因及其蛋白产物来源于腺泡细胞，对β细胞和导管细胞有促有丝分裂作用。我们研究了这种促有丝分裂反应的机制。将ARIP（大鼠导管）和RIN 1046-38（大鼠β-）细胞系暴露于培养物中的外源性reg I或用reg I表达载体转染。通过MTS测定（Cell-Titer 96; Promega，Inc.，麦迪逊，WI），并对细胞mRNA进行基因微阵列分析以确定信号转导途径。酵母双杂交技术检测reg I蛋白的胞内结合。暴露于外源性reg I的细胞表现出促有丝分裂反应;用reg I表达载体转染的细胞表现出生长抑制。微阵列分析显示前者诱导细胞周期蛋白途径和丝裂原活化蛋白激酶磷酸酶（MKP-1）;后者抑制细胞周期蛋白。北方分析证实了细胞周期蛋白D1和MKP-1的基因诱导; JNK在两者表达之前被磷酸化。酵母双杂交分析证实了与MKP-1的蛋白质-蛋白质相互作用;这通过免疫沉淀证实。暴露于reg I的胰腺源性细胞通过激活涉及促分裂原活化蛋白激酶磷酸酶和细胞周期蛋白的信号转导途径生长，同时诱导MKP-1。然而，高细胞内水平的reg I导致生长下降，可能是通过与MKP-1结合和失活。细胞生长的抑制和可能的细胞凋亡的诱导可导致这些细胞分化为其他细胞类型。(c)2008年爱思唯尔公司All rights reserved.
Background. The pancreatic regenerating (reg I) gene and its protein product are derived from acinar cells and are mitogenic to beta- and ductal cells. We studied the mechanism of this mitogenic response.Materials and methods. ARIP (rat ductal) and RIN 1046-38 (rat beta-) cell lines were exposed to exogenous reg I in culture or transfected with a reg I expression vector. Mitogenesis was assessed by MTS assay (Cell-Titer 96; Promega, Inc., Madison, WI), and cellular mRNA was subjected to gene microarray analysis to determine signal transduction pathways. Yeast two-hybrid technology was then used to determine intracellular binding of reg I protein.Results. Cells exposed to exogenous reg I showed a mitogenic response; cells transfected with reg I expression vector showed inhibited growth. Microarray analysis of the former showed induction of cyclin pathways and mitogen-activated protein kinase phosphatase (MKP-1); cyclins were inhibited in the latter. Northern analysis confirmed gene induction of cyclin D1 and MKP-1; JNK was phosphorylated prior to expression of both. Yeast two-hybrid analysis confirmed a protein-protein interaction with MKP-1; this was confirmed by immunoprecipitation.Conclusions. Pancreatic-derived cells exposed to reg I grow by activation of signal transduction pathways involving the mitogen-activated protein kinase phosphatases and cyclins, with concomitant induction of MKP-1. However, high intracellular levels of reg I lead to decreased growth, likely via a binding to and inactivation of MKP-1. Inhibition of cell growth, and possible induction of apoptosis, may lead to differentiation of these cells to other cell types. (c) 2008 Elsevier Inc. All rights reserved.