Cannabinoid Receptor 2 Modulates Neutrophil Recruitment in a Murine Model of Endotoxemia
CB2 knockout mice have increased neutrophils in the spleen at 2 hours following LPS challenge. Male C57BL/6J and CB2 knockout mice (8–10 weeks old) were administered i.p. with 1 mg/kg LPS for 8 hours and neutrophil numbers in the spleen were assessed for 8 hours. Spleen homogenates were stained for neutrophils (CD45+CD11b+Ly-6GhiLy-6C+) by flow cytometry. Representative dot plot graphs from one C57BL/6J (a) and one CB2 knockout (b) mouse gated on CD45+CD11b+ cells are shown for the full time course. Pooled data from two independent experiments with 7–10 mice per group are shown for neutrophils in (c). Mean + SEM are represented in the bar graph, and data were analysed with two-way ANOVA with Sidak’s post hoc multiple comparisons test, . The mRNA levels of (d) Ccl2, (e) Ccl3, (f) Cxcl10, and (g) Il6 were tested by qPCR. Data are pooled from two independent experiments with 8-9 mice per group and 4-5 mice per group per experiment. Mean + SEM are represented in all bar graphs and data were analysed with a one-tailed student t-test, , .