Journal: Cell

Article Title: Astrocytic insulin signaling couples brain glucose uptake with nutrient availability

doi: 10.1016/j.cell.2016.07.028

Figure Lengend Snippet: (A) Mouse brain overview and high magnification depicting the localization of the area infected by AAV5 hGFAP-Cre (GFP-recombined cells under the control of the promoter of hGFAP) and showing GFAP immunoreactivity (red; Alexa 647) in tdTomato/eGFP mice (see also Fig. S3N and Table 2). (B) IR mRNA expression levels corresponding to the hypothalamic region containing virus-targeted astrocytes from C57BL6J mice (n=6) or IRf/f mice (n=5) crossed with tdTomato/eGFP mice, which were injected with AAV-hGFAP-Cre in the MBH. (C) Number of GFAP-positive cells that (co)localize with pAkt in the hypothalamus of IRf/f mice injected with AAV-hGFAP-GFP (Hyp GFAP-IR WT) or AAV-hGFAP-Cre mice (Hyp-GFAP-IR KO) in the MBH 15 min after vehicle (PBS) or insulin injection peripherally (3 U/kg bw; n= 4 mice/group). (D) Images depicting GFAP-positive cells (red; Alexa 555) and pAkt Ser473 (green; Alexa 488) in the hypothalamus of Hyp GFAP-IR WT mice versus Hyp-GFAP-IR KO mice. (E) Blood glucose in Hyp GFAP-IR WT mice (n=9) or Hyp-GFAP-IR KO mice (n=8) after ip glucose. Food intake over the following 4 h in Hyp GFAP-IR WT (F) or Hyp GFAP-IR KO (G) mice in response to vehicle or ip 2DG (n=9–10/group). (H) 4-h accumulated individual changes in food intake after vehicle or ip 2DG in Hyp GFAP-IR WT mice and Hyp GFAP-IR KO mice (n=9–10/group). (I) Glucose and (J) insulin content in blood, (K) glucose content in the CSF and (L) the ratio of glucose between CSF versus blood 30 min after ip vehicle or glucose in GFAP-IR WT mice versus GFAP-IR KO mice (n=4–8/group). (M) 18FDG accumulation in the brain of GFAP-IR WT mice versus GFAP-IR KO mice assessed by positron emission tomography (PET). (N) 18FDG fold change and (O) relative mRNA expression levels of GLUT-1 observed in the brain of GFAP-IR WT mice or GFAP-IR KO (n=4–8/group). (P) Individual changes of 4-h food intake after fasting and icv injection of vehicle (aCSF) or glucose (1 mg) and (Q) individual changes of 4-h food intake after icv injection of vehicle (aCSF) or 2-DG (1 mg) in mice with IR expression in astrocytes in the MBH (Hyp GFAP-IR WT mice; n=10) or without (Hyp GFAP-IR KO mice; n=10). AAV: adeno-associated virus; aCSF: artificial cerebrospinal fluid; GFAP: glial fibrillary acidic protein; GLUT-1: glucose transporter-1; GTT: glucose tolerance test; hGFAP: human glial fibrillary acidic protein; Hyp: hypothalamic; IR: insulin receptor; MBH: the mediobasal hypothalamus; 2DG: 2-deoxy-D-glucose; 18FDG: [18F] fluorodeoxyglucose. P values= ****p<0.0001; ***p<0.001; **p<0.01; *p<0.05. NS: No significant differences between groups. Data are presented as the mean ± SEM. Scale bars: (A): left panel: 1 mm and right panel: 250 μm; (D): 10 μm.

Article Snippet: We stereotaxically injected AAV-hGFAP-GFP (hypothalamic GFAP-IR WT) or AAV–hGFAP-Cre (hypothalamic GFAP-IR KO) particles bilaterally (2×10 9 viral genome particles per side) into the MBH of IR f/f littermates by using a motorized stereotaxic device (Neurostar, Tubingen, Germany).

Techniques: Infection, Expressing, Injection, Positron Emission Tomography