Analysis of Foxo1-regulated genes using Foxo1-deficient pancreatic beta cells

我们产生了具有可诱导Foxo 1缺失的β细胞系。我们产生了一个条件性敲除小鼠品系，其中Cre删除了Foxo 1基因。然后，我们从该敲除小鼠中通过SV 40 T抗原的β细胞特异性表达诱导的胰岛素瘤建立了β细胞系。在该细胞系（命名为MIN 6-Foxo 1flox/flox）中，腺病毒介导的Cre表达消除了Foxo 1基因，产生MIN 6-Foxo 1-KO细胞。使用这些敲除和floxed细胞系，我们发现Foxo 1消融增强了高葡萄糖浓度下葡萄糖刺激的胰岛素分泌（GSIS），并增强了β细胞增殖。我们还进行了MIN 6-Foxo 1-KO细胞感染的腺病毒载体表达的组成型活性FOXO 1或对照载体的DNA微阵列分析，并确定了几个Foxo 1调节基因。这些细胞将有助于进一步研究Foxo 1在β细胞中的作用，并可能导致治疗2型糖尿病的新策略。

We produced a beta-cell line with inducible Foxo1 deletion. We generated a conditional knockout mouse line, in which Cre deletes the Foxo1 gene. We then established a beta-cell line from an insulinoma induced in this knockout mouse by the beta-cell-specific expression of SV40T antigen. In this cell line, designated MIN6-Foxo1flox/flox, adenovirus-mediated Cre expression ablates the Foxo1 gene, generating MIN6-Foxo1-KO cells. Using these knockout and floxed cell lines, we found that Foxo1 ablation enhanced the glucose-stimulated insulin secretion (GSIS) at high glucose concentrations and enhanced beta-cell proliferation. We also conducted DNA microarray analyses of MIN6-Foxo1-KO cells infected with either an adenovirus vector expressing a constitutively active FOXO1 or a control vector and identified several Foxo1-regulated genes. These cells should be useful for further studies on Foxo1's roles in beta-cells and may lead to novel strategies for treatment of type 2 diabetes mellitus.