IL-1β induces ApoE expression in vivo. Proteins were extracted from the left cerebral cortex of unoperated rats (con), of rats implanted in the right cerebrum with a pellet containing vehicle alone (sham), and of rats implanted in the right cerebrum with a slow-release pellet containing 100 ng IL-1β (IL-1β pellet). A: RNA was extracted from the left cerebral cortex of con (n = 6), sham (n = 5), and IL-1β pellet (n = 7) rats and subjected to gel-based RT-PCR for ApoE and GAPDH. B: Quantification of the ApoE mRNA (relative to that for GAPDH) by densitometry of the RT-PCR image or by quantitative (real-time) RT-PCR (qRT-PCR); values reflect the percent of control as mean ± SEM. C: Proteins were extracted from con (n = 3), sham (n = 3), and IL-1β pellet (n = 8) rats and subjected to western immunoblot analysis for ApoE. D: Quantification of autoradiography; values reflect percent of control as mean ± SEM. *p≤0.05; **p < 0.01 versus control.