Fig. 1

The effects of the C-terminal truncation mutants of sTREM2 on microglial responses. A Schematic diagram of a series of C-terminal truncation mutants of sTREM2 fused with human IgG-Fc. B Silver staining analysis of the sTREM2 fragments purified from the conditioned media of transfected HEK293T cells. C, D Primary microglia were treated with 20 nM of Fc alone or the Fc-tagged sTREM2 fragments for 4 h. RNA were extracted, and the relative mRNA levels of IL-1β (C) and TNF (D) were determined by quantitative real-time PCR. β-Actin was used as an internal control (n = 5–8 per group, one-way ANOVA). E Microglia were treated with 20 nM of Fc alone or the Fc-tagged sTREM2 fragments for 24 h after GM-CSF withdrawal. TUNEL was performed to analyze cellular apoptosis (n = 3–6, one-way ANOVA)