Fig. 6
Peripheral immune cells in middle-aged PAE rats display augmented pro-inflammatory cytokine production. a, b Splenic leukocytes and c, d PEC were stimulated in vitro to examine their functional response profiles in proinflammatory cytokine production from Sac vs PAE rats. a Representative flow cytometry plots showing TNFα expression with CD11b/c expression on splenic leukocytes. b Bar graph of proportions of leukocytes displaying intracellular TNFα protein levels following 5 h of PMA/Io stimulation. Proportions of TNFα producing splenic leukocytes were significantly induced in PAE rats [t(5) = 5.6, *p = 0.0025]. , c TNFα levels in the media/cell-free supernatant after 24 h of LPS stimulation of PECs. Both LPS stimulation [F1,24 = 43.13, p <0.0001] and PAE [F1,24 = 10.74, p = 0.0032]  increased TNFα production. A significant interaction between LPS stimulation and PAE was observed [F1,24 = 10.74], p = 0.0032]. LPS stimulated leukocytes from PAE rats induced the greatest amount of TNFα production than LPS stimulated leukocytes from Sac rats. d IL-1β levels in cell lysates of PECs following leukocyte stimulation with LPS. Both LPS stimulation [F1,24 = 31.85, p <0.0001] and PAE[F1,24 = 6.26, p = 0.0196] increased IL-1β production. Following stimulation with LPS, IL-1β production was significantly increased in leukocytes from PAE than leukocytes from Sac rats. N = 6 rats in Sac groups and N = 8 rats in PAE groups. Asterisks indicate p < 0.05. The data are presented as the mean ± SEM