Islet Brain 1 Protects Insulin Producing Cells against Lipotoxicity

Figure 4

Role of Ib1 in apoptosis induced by palmitate. (a) MIN6 cells were transfected with the siRNA duplex directed against IB1 (siIB1) or control siRNA (siGFP, Ctrl) or the plasmids coding for the wild type HA-tagged IB1 (IB1). For scoring death, 0.5 mM palmitate (filled bars) or BSA (Ctrl, open bars) was added to the cells medium 24 hrs after transfection. The rate of apoptosis was scored by counting pycnotic nuclei in cells exposed for 48 hrs to palmitate. Results are expressed as mean ± SEM of 3 independent experiments (; ; ). (b) For the quantification of Bcl2, total RNA from transfected cells with siGFP, siIB1, and IB1 was prepared and subjected to qPCR. The levels of Bcl2 were compared in cells incubated with BSA (open bars) and 0.5 mM palmitate (filled bars) for 48 hrs. The mRNA were normalised against Rplp0 and those of the control cells were set to 100%. Data are the mean ± SEM of five independent experiments ().

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