Fig. 3.

HIP14 is required for β-cell survival. (A) Efficiency of siRNA-mediated knockdown of HIP14 expression in FACS-purified primary β-cells was evaluated by real-time PCR. Data are means ± SEM of n = 5. (B) Primary FACS-purified rat β-cells were left untransfected (control) or transfected with negative control siRNA (si-Neg) or siRNA against HIP14 (si-HIP14). Apoptosis was evaluated using Hoechst/PI staining. Data are means ± SEM of n = 5. (C) INS-1 cells were transfected with pGFP. A transfection efficiency of approximately 50% was obtained. (D) INS-1 cells were transfected with negative control shRNA (sh-Neg) or four different shRNAs directed against HIP14 (sh-HIP14 1–4). Apoptosis was determined by Cell Death Detection ELISA measuring the presence of cytosolic histone–DNA complexes (nucleosomes). Data are means ± SEM of n = 4. *P < 0.05 vs. si-Neg. (E) INS-1 cell growth was measured in real time as described in Materials and Methods. Representative growth curves from cells transfected with si-Neg or si-HIP14 are shown. Each experiment was performed in triplicate. (F) Slopes of growth curves. Data are means ± SEM of n = 3. *P = 0.012.