COUP-TFII regulates β-catenin signaling target genes in mouse islets and a β-cell line.

<p>(A) 832/13 INS-1 β-cells were electroporated with scrambled (control) or COUP-TFII specific siRNA and cultured for 48 h. Levels of cyclin D1, c-myc, glutamine synthase, axin 2, and β-catenin mRNA were determined by RT-qPCR. Effects on Wnt/β-catenin signaling were assessed by the luciferase activity of a TOP/FOP-flash reporter. Results are means ± SEM of data from between 3 and 12 (mRNA levels) independent electroporation experiments. Significant differences between COUP-TFII knockdown and control values are shown by asterisks at the <i>P</i> value indicated. *<i>P</i><0.05; **<i>P</i><0.03. (B) A representative immunoblot of different experiments of 832/13 INS-1 β-cells that were electroporated with scrambled or COUP-TFII specific siRNA. 50 µ g of total protein extract was subjected to immunoblot analysis with antibodies against cyclin D1, CDK4 or β-actin. (C) RT-qPCR analysis of β-catenin and cyclin D1 mRNA levels of 832/13 INS-1 cells infected with Ad-GFP or Ad-hCOUP-TFII at 2 or 5 PFU per cell as indicated <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0030847#pone.0030847-Perilhou1" target="_blank">[4]</a> normalized to housekeeping gene cyclophilin. Results are means ± SEM of data from 3 independent infection experiments. *Significant difference between between COUP-TFII overexpression and control values at <i>P</i><0.05 (D) RT-qPCR analysis of β-catenin, cyclin D1, axin 2, pdx1 and proinsulin I-II mRNA from islets from 5-week-old pdx1^CRE/-, COUP-TFII^Fl/Fl and pdx1^CRE/- COUP-TFII^Fl/Fl mice. Results are mean ± SEM (error bars) for 5 animals per genotype. *P<0.05 for pdx1^CRE/- COUP-TFII^Fl/Fl versus COUP-TFII^Fl/Fl and pdx1^CRE/- control mice.