Enhanced PIP₃ signaling in POMC neurons causes K_ATP channel activation and leads to diet-sensitive obesity
J. Clin. Invest. Leona Plum, et al. 116:1886 doi:10.1172/JCI27123 [Go to this article.]

Figure 1
Generation of PPKO and reporter mice. (A)To visualize Cre-mediated recombination, immunohistochemistry for β-gal was performed in hypothalamic tissues of double-heterozygous reporter mice (PomcCre-RosaArte1). Blue (DAPI), DNA; green, β-gal. (B)Western blot analysis of Pten and insulin receptor β (IR-β) subunit in hypothalamus, brain, liver, pancreas, white adipose tissue (WAT), and skeletal muscle of control (CO) and PPKO mice. (C)PIP₃ formation in hypothalamic neurons of control and PPKO mice. Double immunohistochemistry of ARC neurons of CO_Arte1 and PPKO_Arte1 reporter mice was performed in mice fasted overnight, which were injected intravenously with either saline or insulin and sacrificed 10 and 20 minutes after insulin stimulation. Arrows indicate 1 POMC and 1 non-POMC neuron in each panel. (D)Quantification of PIP₃ levels in control and PPKO POMC neurons in the basal (fasted) state. Values are mean ± SEM of sections obtained from 3 control and 3 PPKO mice. A total of 808 POMC neurons were analyzed. At left are examples of different magnitudes of PIP₃ immunoreactivity (arrowheads) as described in Methods. Blue (DAPI), DNA; red, β-gal (POMC neurons); green, PIP₃. ***P ≤ 0.001 versus control. Scale bars: 100 μm (A), 20 μm (C), 10 μm (D).