Lavine Jeremy A, Raess Philipp W, Davis Dawn Belt, Rabaglia Mary E, Presley Brent K, Keller Mark P, Beinfeld Margery C, Kopin Alan S, Newgard Christopher B, Attie Alan D
Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Mol Endocrinol. 2008 Dec;22(12):2716-28. doi: 10.1210/me.2008-0255. Epub 2008 Oct 9.
Type 1 and type 2 diabetes result from a deficit in insulin production and beta-cell mass. Methods to expand beta-cell mass are under intensive investigation for the treatment of type 1 and type 2 diabetes. We tested the hypothesis that cholecystokinin (CCK) can promote beta-cell proliferation. We treated isolated mouse and human islets with an adenovirus containing the CCK cDNA (AdCMV-CCK). We measured [(3)H]thymidine and BrdU incorporation into DNA and additionally, performed flow cytometry analysis to determine whether CCK overexpression stimulates beta-cell proliferation. We studied islet function by measuring glucose-stimulated insulin secretion and investigated the cell cycle regulation of proliferating beta-cells by quantitative RT-PCR and Western blot analysis. Overexpression of CCK stimulated [(3)H]thymidine incorporation into DNA 5.0-fold and 15.8-fold in mouse and human islets, respectively. AdCMV-CCK treatment also stimulated BrdU incorporation into DNA 10-fold and 21-fold in mouse and human beta-cells, respectively. Glucose-stimulated insulin secretion was unaffected by CCK expression. Analysis of cyclin and cdk mRNA and protein abundance revealed that CCK overexpression increased cyclin A, cyclin B, cyclin E, cdk1, and cdk2 with no change in cyclin D1, cyclin D2, cyclin D3, cdk4, or cdk6 in mouse and human islets. Additionally, AdCMV-CCK treatment of CCK receptor knockout and wild-type mice resulted in equal [(3)H]thymidine incorporation. CCK is a beta-cell proliferative factor that is effective in both mouse and human islets. CCK triggers beta-cell proliferation without disrupting islet function, up-regulates a distinct set of cell cycle regulators in islets, and signals independently of the CCK receptors.
1型和2型糖尿病是由胰岛素分泌不足和β细胞数量减少所致。增加β细胞数量的方法正在深入研究中，用于治疗1型和2型糖尿病。我们验证了胆囊收缩素（CCK）可促进β细胞增殖的假说。我们用携带CCK cDNA的腺病毒（AdCMV - CCK）处理分离的小鼠和人胰岛。我们测量了[³H]胸腺嘧啶核苷和BrdU掺入DNA的情况，此外，还进行了流式细胞术分析以确定CCK过表达是否刺激β细胞增殖。我们通过测量葡萄糖刺激的胰岛素分泌来研究胰岛功能，并通过定量RT - PCR和蛋白质印迹分析研究增殖β细胞的细胞周期调控。CCK过表达分别刺激小鼠和人胰岛中[³H]胸腺嘧啶核苷掺入DNA增加5.0倍和15.8倍。AdCMV - CCK处理也分别刺激小鼠和人β细胞中BrdU掺入DNA增加10倍和21倍。葡萄糖刺激的胰岛素分泌不受CCK表达的影响。细胞周期蛋白和细胞周期蛋白依赖性激酶（cdk）mRNA及蛋白质丰度分析显示，CCK过表达使小鼠和人胰岛中的细胞周期蛋白A、细胞周期蛋白B、细胞周期蛋白E、cdk1和cdk2增加，而细胞周期蛋白D1、细胞周期蛋白D2、细胞周期蛋白D3、cdk4或cdk6无变化。此外，用AdCMV - CCK处理CCK受体敲除小鼠和野生型小鼠，[³H]胸腺嘧啶核苷掺入情况相同。CCK是一种β细胞增殖因子，对小鼠和人胰岛均有效。CCK触发β细胞增殖而不破坏胰岛功能，上调胰岛中一组独特的细胞周期调节因子，且不依赖CCK受体发出信号。
