Fig. 3

IL-33 in hypothalamus was increased by chronic HFD feeding. a The brain sections were prepared from adult mice. The brain sections containing hypothalamic regions were subjected to double immunofluorescence for IL-33 (green) with various glial markers (red) including Iba1 (microglia), GFAP (astrocytes), and Olig2 (OLGs). The nuclear counterstaining by DAPI (blue) was also conducted. The representative images were taken from hypothalamic ARC. The enlarged images from the insets indicated in the upper panel are included in the lower panel. Arrows shown in the lower panel indicate IL-33⁺/GFAP⁺-astrocytes and IL-33⁺/Olig2⁺ OLGs. b Total proteins were prepared from hypothalamus of the obese mice at 3 and 4 month after Chow or HFD feeding, and then subjected to western blot analysis (left-hand panel) to examine IL-33 protein expression. IL-33 protein levels were quantified (right-hand panel). c, d The brain tissue sections were prepared from the Chow- and HFD-fed groups at 4 month after feeding, and then subjected to immunofluorescence. The representative images were captured from ARC regions. Arrows indicate IL-33⁺/GFAP⁺-astrocytes (c) or IL-33⁺/Olig2⁺-OLGs (d). The results shown in b are presented as mean ± SEM (n = 3 animals for each group at each time point). *p < 0.05, ***p < 0.001 versus the Chow group. Scale bar in a, d 50 μm; in c 100 μm