Figure 3. Il4rα KO mice show increased neuronal cell death in the cortical brain slice ischemia assay.

(A – D) Cortical brain slices from Il4rα WT and KO mice biolistically transfected with an YFP expression plasmid under normal conditions and 24 h after 5.5 min of OGD. YFP expressed in cortical pyramidal neurons appears dark in these contrast-inverted fluorescence micrographs. Scale bar: 100 µm. (E) The graph indicates the average cell viability of Il4rα WT and KO before and 24 h after OGD. The OGD dramatically induced neuronal cell death for both Il4rα WT and KO compared their non-OGD control. Experiments were performed three times using three to four mice per genotype for each experiment (Total number of animals: WT (n=10) and KO (n=11)). The number of brain slices analyzed for Il4rα WT(non-OGD), WT (OGD), KO (non-OGD), and KO (OGD) were 55, 58, 62, and 60, respectively. (F) The graph indicates the average cell viability of Il4rα WT and KO 24 h after OGD. Il4rα KO increases neuronal cell death by 40% normalized to Il4rα WT. (G – L) Brain slices for Il4rα WT (G, H, and I) and KO (J, K, and L) were stained with a neuronal-specific MAP2 antibody (G and J) and c-Caspase 3 antibody (H and K). (I) and (L) capture the image of a single neuron located in layer 2/3 of the brain cortex for Il4rα WT (G) and KO (J), and white dots in the outline of the cell represent c-Caspase 3 normalized to the same level of both Il4rα WT and KO neurons using Image J. Scale bar: 5 µm. (M) The graph indicates the average intensity of c-Caspase 3. Il4rα KO neurons showed a 7.7-fold increase in c-Caspase 3 intensity compared to WT neurons. The number of neurons analyzed for Il4rα WT and KO were 10 and 15, respectively. Data represent the mean ± SEM. Statistical analysis, 2-tailed Student’s t test (*** p<.001 vs. Il4rα WT).