Fig. 6: miR-21 promotes Glut2 expression through miR-21-Pdcd4-AP-1 pathway.
From: MicroRNA-21 promotes pancreatic β cell function through modulating glucose uptake
a Pancreatic islets were isolated from 7–8-week-old WT and miR-21βKO mice (n = 3). Pdcd4 mRNA expression was determined by quantitative RT-PCR. Data are presented as means ± SD for n = 3 biologically independent samples. b, c Pancreatic islets were isolated from 7–8-week-old WT or miR-21βKO mice (n = 3) and protein expression of Pdcd4 (b) and c-Jun (c) were determined by western blotting. d, e β–TC-6 cells were transfected with either universal negative control siRNA duplex (NC) or siRNA duplex targeting mouse Pdcd4 (siPdcd4). Protein levels of Pdcd4 (d) and Glut2 (e) were examined by western blotting. f β–TC-6 cells were transiently transfected with mouse Glut2 promoter luciferase reporter together with c-Jun expression vector (pRK5-c-Jun) or empty vector (pRK5). The luciferase activities of total cell lysates were measured using the Dual-Luciferase Reporter Assay system. Co-transfection of the Renilla luciferase expression vector pRL-TK was used as an internal control. g β-TC-6 cells were transfected with c-Jun expression vector (pRK5-c-Jun) or empty vector (pRK5). Alternatively, β-TC-6 cells were treated with DMSO or AP-1 inhibitor T-5224. Glut2 mRNA was determined by quantitative RT-PCR. For both (f) and (g), data are presented as means ± SD for n = 3 biologically independent samples. h β-TC-6 cells were transfected with c-Jun expression vector (pRK5-c-Jun) or empty vector (pRK5). Glut2 protein level was determined by western blotting. i Pancreatic islets were treated with DMSO or AP-1 inhibitor T-5524 and Glut2 protein level was determined by western blotting. j Schematic illustration of how miR-21 promotes Glut2 expression in islet β cells. All statistical significance was analyzed using two-sided unpaired t test and P values are indicated in the figure. All results are representative of at least two independent experiments. Equal numbers of male and female mice were used in two genotypes. Source data are provided as a Source Data file.
