Fig. 2

DSS-treated mice exhibit increased neuroinflammation but not immune cell infiltration in the brain. Bioluminescence was quantified from brain tissue harvested from caspase reporter mice either treated with normal drinking water (control) or 2% DSS for 7 days, or injected with LPS (100 μg, 24 h) (A). 200 μm organotypic slice cultures were generated from control or DSS brains and after one week in vitro, luciferase signal was measured using the IVIS (B). Brains were isolated from control or DSS mice, or mice injected i.p with 100 μg LPS for 24 h. Tissues were homogenized and caspase-1 expression was measured in lysates by western blot (C). Whole brains were sectioned into the indicated regions and BDNF, TNFα, IL-1β and KC levels were measured by ELISA or qRT-PCR, n = 5–8 animals/group (D). Brains were homogenized, lysed and equal amounts of protein lysates were incubated with the mouse cytokine detection antibodies and applied to nitrocellulose membranes pre-coated with 40 different anti-cytokine antibodies in duplicate and protein expression was measured by chemiluminescence (E). Green boxes indicate reference control. Mean pixel intensity of KC (red box) was quantified using ImageJ (F). CBA was performed on brain homogenates and KC expression was quantified (G). Brains isolated from control, DSS and LPS-treated mice were digested and isolated cells were stained for flow cytometric analysis of the indicated immune cell populations, following the gating strategy depicted in Additional file 4 (specifically live, CD45 + , subgated on markers for the indicated immune cell population) (H). Brains were fixed, stained with anti-Iba1 antibody, clarified and imaged using a light sheet microscope (I). Representative images from each group, low min signal panels on the top and high min signal panels on the bottom (I). Student’s t test comparing DSS or LPS to control. *** = p < 0.0005, ** = p < 0.005, * = p < 0.05