Fig. 4.

mSOD1^G93A activates microglia through CD14. A: Immunoprecipitation with anti-CD14 antibody and subsequent western blot with anti-SOD1 antibody showed binding of mSOD1^G93A to rCD14 was greater than SOD1^WT. Negative control included incubation of mSOD1^G93A only or rCD14 only with anti-CD14 antibody. B-G: The blocking CD14 antibody (1 μg/ml) attenuated mSOD1^G93A-induced microglial activation by suppressing the release of TNF-α (B), IL-1β (C), NOX2 mRNA (D), superoxide (E), iNOS expression (F), and increasing the production of free IGF-1 (G). H: WT or CD14^−/− microglia were treated with 1 μg/ml SOD1^WT or mSOD1^G93A for 2 days. mSOD1^G93A induced CD14^−/− microglia to produce less TNF-α than WT microglia. Data shown as mean±SE of at least three independent experiments with duplicate or triplicate wells. Mc = microglia; SOD1^WT = wild-type SOD1; mSOD1^G93A = mutant SOD1^G93A; Ab = antibody. *p<0.05; **p<0.01 vs untreated microglia; ^##p<0.01 vs SOD1^WT-treated microglia; ^&p<0.05; ^&&p<0.01 vs mSOD1^G93A-treated microglia.