Lipotoxic Stress Induces Pancreatic β-Cell Apoptosis through Modulation of Bcl-2 Proteins by the Ubiquitin-Proteasome System

Figure 5

Palmitate and MG132 activate AKT and PUMA in pancreatic β-cells. ((a)-(b)) MIN6 cells were treated with 0.5 mM palmitate (a) or 10 μM MG132 (b) as indicated and expression of p-AKT was measured by Western blot. Band intensities were quantified and values of the specific time points standardised to β-actin loading controls. ((c)-(d)) MIN6 cells were treated with 0.5 mM palmitate (c) or 10 μM MG132 (d) and expression of PUMA was measured by qPCR. (e) Islets were obtained from wild-type C57BL/6 and PUMA mice and treated with 10 μM MG132 for 24 h and subsequent levels of cell death were determined by FACS analysis. Results are the means ± SEM of 3–5 independent experiments. , , and .

(a)

(b)

(c)

(d)

(e)