Fig. 5

Neutralization of TNFα restores remyelination in mice injected with citrullinated myelin. A Primary microglia were incubated for 24 h with vehicle (VEH), unmodified myelin (UNMOD), or citrullinated myelin (CIT). TNFα levels were measured by cytometric bead array in supernatants. Each symbol represents one culture well replicate from several experiments. B Microglia were incubated with 50, 25, 12.5, or 6.25 μg/mL citrullinated myelin and TNFα levels were assessed after 24 h. C Microglia were exposed to pure citrulline (1.75 μg/mL), pure PAD2 enzyme (50 ng/mL), or IFNγ (200 ng/mL) and TNFα levels were assessed after 24 h. C = citrulline, P = PAD2, I = IFNγ D Mice were injected with VEH, UNMOD myelin, or CIT myelin and then a 4 mm diameter cylinder of cortical tissue around the injection site was extracted after 24 h and processed for measurement of TNFα levels. Each symbol represents one animal. E After 6 weeks on cuprizone chow, mice were switched to normal chow, injected intraperitoneally with TNFα neutralizing antibody (+ IgG) or isotype control (− IgG), and injected intracranially with UNMOD or CIT myelin. Remyelination was assessed by MBP-positive surface area in cortical sections 3 weeks later. A remyelination index was calculated by dividing the MBP surface area from each animal by the mean MBP surface area in all vehicle-injected mice. A control group receiving only anti-TNFα and no intracranial injection (NO IC) was included. Each symbol represents one animal. Graphs show mean ± 95% CI. Statistical comparisons not shown were insignificant