Fig. 7

Astrocyte tmTNF-neuronal TNFR2 interactions are necessary for TNF neuroprotection against NMDA excitotoxicity in vitro. (A and B) Addition of hTNF in astrocyte-neuron co-cultures made from different combinations of WT, TNFKO, and TNFRKO mice 24 h before NMDA-induced cell death. Specifically, neuron-astrocyte co-cultures at day in vitro 7 of co-culture (NA-DIV7) were pretreated with 100 ng/ml hTNF for 24 h, NMDA excitotoxic death was induced with 50 μΜ NMDA/10 μΜ glycine on NA-DIV8, and death was measured after 22 h at NA-DIV9. (C) Addition of a TNFR2ag in NA-DIV7 co-cultures made from WT mice 24 h before NMDA-induced excitotoxicity provides equal neuroprotection against NMDA-induced cell death as hTNF. As control, NMDA-induced neuronal death was completely inhibited by pretreatment with the NMDA receptor antagonist MK801. Results shown are means ± SEM of duplicate or triplicate samples from one representative of two or three independent experiments. *p ≤ 0.05, **p ≤ 0.005, ***p ≤ 0.001, for pairwise comparisons between cells in each genotype combination by Student’s t-test