Research Paper Volume 8, Issue 3 pp 484—505

MicroRNA-15b regulates mitochondrial ROS production and the senescence-associated secretory phenotype through sirtuin 4/SIRT4

class="figure-viewer-img"

Figure 7. Analysis of the expression of SIRT4 and its colocalization with the mitochondrial marker MTCO2 in human dermal fibroblasts upon transfection of miR-15b inhibitors. (A) Modulation of SIRT4 expression via transfection of miR-15b inhibitors in the absence or presence of siRNA duplexes against SIRT4 (mean ± s.d. from nine to twelve experiments). (B) ELISA-based quantification of relative SIRT4 protein levels (suppl. Material & Methods) in fibroblasts transfected with miR-15b inhibitors in the absence or presence of siRNA duplexes against SIRT4 (mean ± s.d. from four experiments). To evaluate statistical significance, ANOVA SNK was performed. (C) Confocal microscopy-based visualization of the mitochondrial marker MTCO2 (green) and SIRT4 (red) in miR-15b inhibitor-transfected fibroblasts as compared to control cells. Total SIRT4 signal intensities were normalized to MTCO2 in miR-15b inhibitor-transfected cells in the absence (D) or presence (E) of siRNA duplexes against SIRT4 using ImageJ software. Mean ± s.d. from four (D) and three (E) independent experiments. Thirty to fifty cells were analysed per experiment and condition. To evaluate statistical significance, ANOVA on ranks Dunn´s tests were performed (*p<0.05).